April 23rd, 2021

Do Chron Your Factory Ammo — Stated Velocities May Be Wrong

muzzle velocity applied Ballistics MV chronograph

Why You CANNOT Rely on the MV Printed on the Ammo Box!
When figuring out your come-ups with a ballistics solver or drop chart it’s “mission critical” to have an accurate muzzle velocity (MV). When shooting factory ammo, it’s tempting to use the manufacturer-provided MV which may be printed on the package. That’s not such a great idea says Bryan Litz of Applied Ballistics. Don’t rely on the MV on the box, Bryan advises — you should take out your chrono and run your own velocity tests. There are a number of reasons why the MV values on ammo packaging may be inaccurate. Below is a discussion of factory ammo MV from the Applied Ballistics Facebook Page.

Five Reasons You Cannot Trust the Velocity on a Box of Ammo:

1. You have no idea about the rifle used for the MV test.

2. You have no idea what atmospheric conditions were during testing, and yes it matters a lot.

3. You have no idea of the SD for the factory ammo, and how the manufacturer derived the MV from that SD. (Marketing plays a role here).

4. You have no idea of the precision and quality of chronograph(s) used for velocity testing.

5. You have no idea if the manufacturer used the raw velocity, or back-calculated the MV. The BC used to back track that data is also unknown.

1. The factory test rifle and your rifle are not the same. Aside from having a different chamber, and possibly barrel length some other things are important too like the barrel twist rate, and how much wear was in the barrel. Was it just recently cleaned, has it ever been cleaned? You simply don’t know anything about the rifle used in testing.

2. Temperature and Humidity conditions may be quite different (than during testing). Temperature has a physical effect on powder, which changes how it burns. Couple this with the fact that different powders can vary in temp-stability quite a bit. You just don’t know what the conditions at the time of testing were. Also a lot of factory ammunition is loaded with powder that is meter friendly. Meter friendly can often times be ball powder, which is less temperature stable than stick powder often times.

3. The ammo’s Standard Deviation (SD) is unknown. You will often notice that while MV is often listed on ammo packages, Standard Deviation (normally) is not. It is not uncommon for factory ammunition to have an SD of 18 or higher. Sometimes as high as 40+. As such is the nature of metering powder. With marketing in mind, did they pick the high, low, or average end of the SD? We really don’t know. You won’t either until you test it for yourself. For hand-loaded ammo, to be considered around 10 fps or less. Having a high SD is often the nature of metered powder and factory loads. The image below is from Modern Advancements in Long Range Shooting: Volume II.

muzzle velocity applied Ballistics MV chronograph

4. You don’t know how MV was measured. What chronograph system did the manufacturer use, and how did they back track to a muzzle velocity? A chronograph does not measure true velocity at the muzzle; it simply measures velocity at the location it is sitting. So you need to back-calculate the distance from the chrono to the end of the barrel. This calculation requires a semi-accurate BC. So whose BC was used to back track to the muzzle or did the manufacturer even do that? Did they simply print the numbers displayed by the chronograph? What kind of chronograph setup did they use? We know from our Lab Testing that not all chronographs are created equal. Without knowing what chronograph was used, you have no idea the quality of the measurement. See: Applied Ballistics Chronograph Chapter Excerpt.

5. The MV data may not be current. Does the manufacturer update that data for every lot? Or is it the same data from years ago? Some manufacturers rarely if ever re-test and update information. Some update it every lot (ABM Ammo is actually tested every single lot for 1% consistency). Without knowing this information, you could be using data for years ago.

CONCLUSION: Never use the printed MV off a box of ammo as anything more than a starting point, there are too many factors to account for. You must always either test for the MV with a chronograph, or use carefully obtained, live fire data. When you are using a Ballistic Solver such as the AB Apps or Devices integrated with AB, you need to know the MV to an accuracy down to 5 fps. The more reliable the MV number, the better your ballistics solutions.

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April 20th, 2021

LabRadar Owners — You Should Get this $35 Inertial Trigger

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

SUMMARY: This article reviews a device that “triggers” the LabRadar chronograph to register bullet speed. Rather than activate by sound or Doppler reading, this $35 JKL Inertial Trigger works from the rifle’s instantaneous recoil pulse when a shot is fired. After some frustration with his LabRadar when shooting at a range with reflective surfaces, our tester is now reporting that 100% of his actual shots are being captured correctly by his LabRadar chrono equipped with the JKL Inertial Trigger. He won’t use his LabRadar without it now. Other users have become instant fans of this inertial LabRadar trigger as well. It is very affordable and it works great. VIEW LARGE PHOTO.

JKL Inertial Trigger for LabRadar Chronograph

Product Review by F Class John
The LabRadar chronograph has been one of the most revolutionary tools in the shooting world because of how it collects velocity data, how it reports (and stores) that data, and, ultimately, the ease with which it can be positioned and operated. However, it’s not a perfect system. A majority of the complaints come from users whose LabRadar’s sometimes fail to record all the shots fired in a string. For the average plinker, this may not be an issue. But for serious shooters trying to do ladder tests or load development requiring all shots to be reported, it can be frustrating when a shot is missed.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

Traditionally, LabRadar has recommended trying different settings that compensate for the gap between the unit and muzzle as well as well as having different options for how the unit recognizes a shot fired. While these options work to some degree, they aren’t a guaranteed fix especially when shooting at ranges with concrete baffles or with roofs, walls, and dividers that can alter sound waves. While nobody can precisely explain why shots are lost under certain circumstances, the fact remains it DOES happen. In addition, the default system can sometimes pick up stray shots from nearby rifles.

Not willing to give up on this sophisticated chronograph, many shooters have looked for a foolproof way to prevent such failures from happening. In fact, for this shooter, the frustration was so high that I actually sold my first LabRadar and went back to another chronograph before ultimately buying another LabRadar almost a year later. But I made that repeat purchase only after vowing to finding a way to make the LabRadar work — EVERY time, for EVERY shot.

See How JKL Inertial Trigger Works in this Video

JKL Inertial Trigger — Outstanding Product That Works Great
Enter the JKL Trigger for the LabRadar. This is an easy-to-use, inertial-driven trigger that activates simply from the recoil of your gun. The unit consists of a small rectangular pad attached to a long audio cable. All you do is plug in the audio cable, attach the pad to your gun with the provided hook and loop (Velcro) material. Then (important), you must change the LabRadar trigger settings from “Doppler” to “Trigger”. The unit works great and is easy to set up. In my experience, the unit will activate no matter where you place it on a stock. However the recoil of every gun is slightly different, so you will need to make sure you find a location that doesn’t interfere with your shooting setup.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

An unexpected benefit of using the JKL trigger is that it gives you a larger area in which to place your Labradar unit, making it more convenient to setup on benches or range stations. I found this a welcome relief since the LabRadar originally seemed somewhat fussy about where I placed it. Now I can place the LabRadar in more convenient locations — as long as it’s still near my gun and pointed at the target correctly, I get consistent bullet speed data.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

Are There Issues with “False Positives”?
If there is any downside to using the JKL Inertial Trigger, it’s that a very hard bump or aggressive working of the action can trigger a false reading. However these are easy to identify in your data, because the speed value is way lower than true fired shot values. Simply remove that low entry or otherwise ignore it in your calculations. To be fair, this “bump activation” really doesn’t happen very often once you get used to using the inertial trigger.

SUMMARY — Outstanding Accessory for LabRadar Users
Bottom line — if you own a LabRadar, then definitely get a JKL Inertial Trigger. Priced at just $35.00 this device is not expensive, yet it’s one of the most effective accessories you can buy for the LabRadar. I’ve recommended these inertial triggers to dozens of shooters. Every one of those guys who did buy a JKL trigger says they can’t imagine using a LabRadar without one. If you love what the LabRadar can do, but have been frustrated with shots not getting recorded 100% of the time, then definitely get yourself a JKL Inertial Trigger. It turns a good system into an amazing system. JKL Industries states that its inertial trigger “will work on anything from a .22 LR to a suppressed system or with standard rifle and brake.”

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March 18th, 2021

Get Smart — Read FREE Applied Ballistics TECH Articles

Want to improve your understanding of Ballistics, Bullet Design, Bullet Pointing, and other shooting-related tech topics? Well here’s a treasure trove of gun expertise. Applied Ballistics offers dozens of FREE tech articles on its website. Curious about Coriolis? — You’ll find answers. Want to understand the difference between G1 and G7 BC? — There’s an article about that.

“Doc” Beech, technical support specialist at Applied Ballistics says these articles can help shooters working with ballistics programs: “One of the biggest issues I have seen is the misunderstanding… about a bullet’s ballistic coefficient (BC) and what it really means. Several papers on ballistic coefficient are available for shooters to review on the website.”

Credit Shooting Sports USA Editor John Parker for finding this great resource. John writes: “Our friends at Applied Ballistics have a real gold mine of articles on the science of accurate shooting on their website. This is a fantastic source for precision shooting information[.] Topics presented are wide-ranging — from ballistic coefficients to bullet analysis.”

READ All Applied Ballistics Articles HERE »

Here are six (6) of our favorite Applied Ballistics articles, available for FREE to read online. There are dozens more, all available on the Applied Ballistics Education Webpage. After Clicking link, select Plus (+) Symbol for “White Papers”, then navigate with L/R arrows.

Permalink - Articles, Bullets, Brass, Ammo, Reloading, Tech Tip 2 Comments »
March 4th, 2021

MagnetoSpeed Sporter — Great Chronograph Value

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $180.00 from Brownells. You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution. Be aware, however, that the placement of the Sporter Chrono ON the barrel can affect barrel harmonics. Therefore you should do your final load testing without the Sporter attached.

See MagnetoSpeed Sporter Chronograph Features Reviewed in Video

We’re impressed by the Sporter chrono, as are other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).

The MagnetoSpeed Sporter chrono is less than half the price of previous MagnetoSpeed models. This is great for shooters who always wanted a MagnetoSpeed but found the higher-end V3 Model too pricey at $380.00. The Sporter Chronograph costs just $179.00 at Brownells and $178.99 at Amazon.

The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says the Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.

Available NOW: MagnetoSpeed Sporter $179.00 at Brownells and $178.99 at Amazon.

Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?

A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.

Click Image for Full-Screen Photo
magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

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November 7th, 2020

MagnetoSpeed Sporter Chrono — Great Performance and Value

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $160.00! You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution.

See MagnetoSpeed Sporter Chronograph Features Reviewed in Video

We’re impressed by the Sporter chrono, as are other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).

The MagnetoSpeed Sporter chrono is less than half the price of previous MagnetoSpeed models. This is big news for shooters who always wanted a MagnetoSpeed but found the $379.00 cost (for V3 model) too pricey. The Sporter Chronograph costs just $159.99 at MidwayUSA (see below) and $179.00 at Amazon.

The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says its new Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.

Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?

A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen.. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.

Click Image for Full-Screen Photo
magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

Magnetospeed sporter MidwayUSA chron chronograph

This post essentially puts twenty bucks in your pocket if you need a chronograph. You see the MagnetoSpeed Sporter Chrono typically costs around $180.00 from most vendors. But right now MidwayUSA is running a special — the true “shopping cart price” is $159.99. That’s $20.00 cheaper than Midway’s regular $179.99 price, and $19.00 cheaper than the lowest price we found anywhere else. But this special “Shopping Cart Discount” may not last long, so you may want to act quickly. We confirmed Midway’s $159.99 price on the morning of November 7, 2020.

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September 24th, 2020

MagnetoSpeed V3 Chronograph Review and Test Video

Gavin Gear Magnetospeed V3 Chronograph ultimatereloader.com

MagnetoSpeed’s technology has completely changed the market for firearms chronographs. With a MagnetoSpeed barrel-mounted chrono you can quickly and easily record muzzle velocity (MV) without having to set up tripods or walk down-range. The compact MagnetoSpeed chronos are easy to set up and transport. With the full-featured V3 model, everything you need comes in a small fitted case. In the top photo are the components used with the MagnetoSpeed V3 Kit:

1. V3 Bayonet sensor
2. Display and control unit
3. Bayonet spacers (plastic and rubber)
4. Cords and mounting hardware (left), suppressor heat shield (right)
5. Alignment rod (square cross-section)
6. Rail adapter (sold separately)

Our friend Gavin Gear of UltimateReloader.com reviewed the MagnetoSpeed V3 and came away impressed. Gavin explains that a good chrono is essential: “If you want to load and shoot precision ammunition, you need the tools that will produce and validate the precision of your loads. A good chronograph is one of those tools! In this post I’m going to introduce you to the MagnetoSpeed V3 chonograph, the high-end electromagnetic chronograph which fills out the top slot in MagnetoSpeed’s equipment portfolio.”

In this 11-minute video Gavin reviews MagnetoSpeed’s top-of-the-line V3 Chronograph. He shows what ships with the unit, how to set it up for both rifles and pistols, and then he puts it through its paces showing how it captures velocity data. Gavin says he will follow-up with future videos showing how to link the MagnetoSpeed V3 to your mobile phone and how to log velocity data for future reference. To learn more about this high-tech chrono, visit UltimateReloader.com.

READ Full MagnetoSpeed V3 Review on UltimateReloader.com

Gavin Gear Magnetospeed V3 Chronograph ultimatereloader.com

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May 12th, 2020

JKL Inertial Trigger — Great Upgrade for LabRadar Chronograph

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

SUMMARY: This article reviews a device that “triggers” the LabRadar chronograph to register bullet speed. Rather than activate by sound or Doppler reading, this $35 JKL Inertial Trigger works from the rifle’s instantaneous recoil pulse when a shot is fired. After some frustration with his LabRadar when shooting at a range with reflective surfaces, our tester is now reporting that 100% of his actual shots are being captured correctly by his LabRadar chrono equipped with the JKL Inertial Trigger. He won’t use his LabRadar without it now. Other users have become instant fans of this inertial LabRadar trigger as well. It is very affordable and it works great. VIEW LARGE PHOTO.

JKL Inertial Trigger for LabRadar Chronograph

Product Review by F Class John
The LabRadar chronograph has been one of the most revolutionary tools in the shooting world because of how it collects velocity data, how it reports (and stores) that data, and, ultimately, the ease with which it can be positioned and operated. However, it’s not a perfect system. A majority of the complaints come from users whose LabRadar’s sometimes fail to record all the shots fired in a string. For the average plinker, this may not be an issue. But for serious shooters trying to do ladder tests or load development requiring all shots to be reported, it can be frustrating when a shot is missed.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

Traditionally, LabRadar has recommended trying different settings that compensate for the gap between the unit and muzzle as well as well as having different options for how the unit recognizes a shot fired. While these options work to some degree, they aren’t a guaranteed fix especially when shooting at ranges with concrete baffles or with roofs, walls, and dividers that can alter sound waves. While nobody can precisely explain why shots are lost under certain circumstances, the fact remains it DOES happen. In addition, the default system can sometimes pick up stray shots from nearby rifles.

Not willing to give up on this sophisticated chronograph, many shooters have looked for a foolproof way to prevent such failures from happening. In fact, for this shooter, the frustration was so high that I actually sold my first LabRadar and went back to another chronograph before ultimately buying another LabRadar almost a year later. But I made that repeat purchase only after vowing to finding a way to make the LabRadar work — EVERY time, for EVERY shot.

See How JKL Inertial Trigger Works in this Video

JKL Inertial Trigger — Outstanding Product That Works Great
Enter the JKL Trigger for the LabRadar. This is an easy-to-use, inertial-driven trigger that activates simply from the recoil of your gun. The unit consists of a small rectangular pad attached to a long audio cable. All you do is plug in the audio cable, attach the pad to your gun with the provided hook and loop (Velcro) material. Then (important), you must change the LabRadar trigger settings from “Doppler” to “Trigger”. The unit works great and is easy to set up. In my experience, the unit will activate no matter where you place it on a stock. However the recoil of every gun is slightly different, so you will need to make sure you find a location that doesn’t interfere with your shooting setup.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

An unexpected benefit of using the JKL trigger is that it gives you a larger area in which to place your Labradar unit, making it more convenient to setup on benches or range stations. I found this a welcome relief since the LabRadar originally seemed somewhat fussy about where I placed it. Now I can place the LabRadar in more convenient locations — as long as it’s still near my gun and pointed at the target correctly, I get consistent bullet speed data.

LabRadar chronograph to register bullet speed JKL inertial trigger recoil activated

Are There Issues with “False Positives”?
If there is any downside to using the JKL Inertial Trigger, it’s that a very hard bump or aggressive working of the action can trigger a false reading. However these are easy to identify in your data, because the speed value is way lower than true fired shot values. Simply remove that low entry or otherwise ignore it in your calculations. To be fair, this “bump activation” really doesn’t happen very often once you get used to using the inertial trigger.

SUMMARY — Outstanding Accessory for LabRadar Users
Bottom line — if you own a LabRadar, then definitely get a JKL Inertial Trigger. Priced at just $35.00 this device is not expensive, yet it’s one of the most effective accessories you can buy for the LabRadar. I’ve recommended these inertial triggers to dozens of shooters. Every one of those guys who did buy a JKL trigger says they can’t imagine using a LabRadar without one. If you love what the LabRadar can do, but have been frustrated with shots not getting recorded 100% of the time, then definitely get yourself a JKL Inertial Trigger. It turns a good system into an amazing system. JKL Industries states that its inertial trigger “will work on anything from a .22 LR to a suppressed system or with standard rifle and brake.”

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April 7th, 2020

How Ammo Temp Can Affect Velocity — Freezing to 130 degrees F

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold
In this .308 Win test, 70° F ammo shot 96 FPS slower than ammo heated to 130.5° F. And the 130.5° ammunition was 145 fps faster than ammo taken right out of the freezer (at 25.5° F). That’s a huge difference…

EDITOR’s NOTE: The Sierra tester does not reveal the brand of powder tested here. Some powders are much more temp sensitive than others. Accordingly, you cannot extrapolate test results from one propellant to another. Nonetheless, it is interesting to see the actual recorded velocity shift with ammo temperature variations in a .308 Win.

Written by Sierra Chief Ballistician Tommy Todd
This story originally appeared in the Sierra Bullets Blog
A few weeks ago I was attending the Missouri State F-Class Match. This was a two-day event during the summer and temperatures were hot one day and hotter the next. I shot next to a gentleman who was relatively new to the sport. He was shooting a basically factory rifle and was enjoying himself with the exception that his scores were not as good as he hoped they would be and he was experiencing pressure issues with his ammunition. I noticed that he was having to force the bolt open on a couple of rounds. During a break, I visited with him and offered a couple of suggestions which helped his situation somewhat and he was able to finish the match without major issues.

He was shooting factory ammunition, which is normally loaded to upper levels of allowable pressures. While this ammunition showed no problems during “normal” testing, it was definitely showing issues during a 20-round string of fire in the temperatures we were competing in. My first suggestion was that he keep his ammunition out of the direct sun and shade it as much as possible. My second suggestion was to not close the bolt on a cartridge until he was ready to fire. He had his ammo in the direct sunlight and was chambering a round while waiting on the target to be pulled and scored which can take from a few seconds to almost a minute sometimes.

This time frame allowed the bullet and powder to absorb chamber [heat] and build pressure/velocity above normal conditions. Making my recommended changes lowered the pressures enough for the rifle and cartridge to function normally.

Testing Effects of Ammunition Temperature on Velocity and POI
After thinking about this situation, I decided to perform a test in the Sierra Bullets underground range to see what temperature changes will do to a rifle/cartridge combination. I acquired thirty consecutive .30 caliber 175 grain MatchKing bullets #2275 right off one of our bullet assembly presses and loaded them into .308 Winchester ammunition. I utilized an unnamed powder manufacturer’s product that is appropriate for the .308 Winchester cartridge. This load is not at the maximum for this cartridge, but it gives consistent velocities and accuracy for testing.

I took ten of the cartridges and placed them in a freezer to condition.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I set ten of them on my loading bench, and since it was cool and cloudy the day I performed this test I utilized a floodlight and stand to simulate ammunition being heated in the sun.

Sierra Bullets Ammunition Ammo temperature temp test hot F-Class Ammo cold

I kept track of the temperatures of the three ammunition samples with a non-contact laser thermometer.

The rifle was fired at room temperature (70 degrees) with all three sets of ammunition. I fired this test at 200 yards out of a return-to-battery machine rest. The aiming point was a leveled line drawn on a sheet of paper. I fired one group with the scope aimed at the line and then moved the aiming point across the paper from left to right for the subsequent groups.

NOTE that the velocity increased as the temperature of the ammunition did.

The ammunition from the freezer shot at 2451 fps.

Frozen FPS

The room temperature ammunition shot at 2500 fps.

Room Temperature FPS

The heated ammunition shot at 2596 fps.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

The tune window of the particular rifle is fairly wide as is shown by the accuracy of the three pressure/velocity levels and good accuracy was achieved across the board. However, notice the point of impact shift with the third group? There is enough shift at 200 yards to cause a miss if you were shooting a target or animal at longer ranges. While the pressure and velocities changed this load was far enough from maximum that perceived over pressure issues such as flattened primer, ejector marks on the case head, or sticky extraction did not appear. If you load to maximum and then subject your ammunition to this test your results will probably be magnified in comparison.

Sierra Bullets Ammunition Ammo temperature temp test hot cold

This test showed that pressures, velocities, and point-of-impact can be affected by temperatures of your ammunition at the time of firing. It’s really not a bad idea to test in the conditions that you plan on utilizing the ammo/firearm in if at all possible. It wouldn’t be a bad idea to also test to see what condition changes do to your particular gun and ammunition combination so that you can make allowances as needed. Any personal testing along these lines should be done with caution as some powder and cartridge combination could become unsafe with relatively small changes in conditions.

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March 20th, 2020

MagnetoSpeed Sporter — On Sale for under $158

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $158.00. You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution.

See MagnetoSpeed Sporter Chronograph Features Reviewed in Video

We like the Sporter chrono, as do other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).

The MagnetoSpeed Sporter is less than half the price of previous MagnetoSpeed models. This is big news for shooters who always wanted a MagnetoSpeed but found the $379.00 cost (for V3 model) too pricey. The new Sporter Chronograph costs just $157.71 at Midsouth Shooters and $179.00 at Amazon.

The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says its new Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.

Available NOW: MagnetoSpeed Sporter $157.71 at Midsouth Shooters and $179.00 at Amazon.

Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?

A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen.. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.

Click Image for Full-Screen Photo
magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

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December 19th, 2019

How NOT to Ventilate Your Costly Chronograph — Set-UP Tips

accurateshooter.com target chrony shoot chronograph damage chrono

“Shooting Chrony” is a product name. “Shooting Chrony” should not describe (post-mortem) what you have been doing to your chronograph. Sooner or later all of us may make a mistake, and ventilate our chronograph. With luck, the bullet just “wings” your chronograph, and the damage is minor. But if you hit the unit smack dab in the middle, you may have to retire your chrono for good.

A while back, Forum member Jeff M. (aka “JRM850″) experienced a “low blow” that put his Shooting Chrony out of commission. With tongue firmly in cheek, Jeff started a Forum thread entitled Chronograph Not Picking Up Shots in Bright Sunlight Anymore. Looking at the photo at top, the problem is obvious — he ventilated his Chrono.

This was Jeff’s first chrono kill in 23 years of use, so we shouldn’t be too critical. Jeff explained: “I didn’t realize a friend was shifting from a 300-yard target to 100 yards.” The agent of destruction was a low-traveling 58gr V-Max running at 3415 fps. What happened? Well, when one is shooting at 300 yards, the trajectory will be higher than at 100 yards. We should say, however, that this may have been a low shot, or the 100-yard aiming point may have been placed lower to the ground (closer to the bottom of the target frame), as compared to the 300-yard aiming point.

Other Forum members offered some sarcastic responses:

Try it on an overcast day – it might work again.

It looks like the V-Max performed just about as advertised.

Aww…a little duct tape and some Super Glue and you’re good to go.

If you are using a LabRadar or Magnetospeed, your chrono shouldn’t be in the line of fire, but for those will conventional chronos, here’s some good advice…

Double Check Your Aim Point and Trajectory BEFORE You Shoot
The lesson learned here is that you should never change targets (or aim points) without checking your bullet’s flight over the chronograph. We like to align the barrel so the bullet exits a good 6-8 inches above the electronics (check your manual for recommended shot height).

In addition, we always boresight the barrel so we can see the actual target through the bore. Then, with gun UNLOADED, bolt removed and action clear, we look back down the barrel so we can see daylight through the bore, with the gun set on solid rests. If you look through the middle of the “V” formed by the sky screen supports and you can’t see light shining through the barrel’s bore, you probably have a set-up problem and you should re-align the rifle.

accurateshooter.com target chrony shoot chronograph damage chrono

Use a Test Backer to Confirm Your Bullet Trajectory
You can put tape on the support rods about 6″ up from the unit. This helps you judge the correct vertical height when setting up your rifle on the bags. Another trick is to hang a sheet of paper from the rear skyscreen and then use a laser boresighter to shine a dot on the paper (with the gun planted steady front and rear). This should give you a good idea (within an inch or so) of the bullet’s actual flight path through the “V” over the light sensors. Of course, when using a laser, never look directly at the laser! Instead shine the laser away from you and see where it appears on the paper.

After you have used the laser boresighter to get the rifle centered up in the chrono’s “sweet spot”, confirm with a test shot or two (see photo). Even when using an in-chamber laser boresighter, it is not uncommon for the bullet’s actual point of impact to be different than the laser’s dot location.

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November 17th, 2019

Chrono Test — LabRadar vs. MagnetoSpeed vs. Oehler 35P

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

We see comparison tests of cars, cameras, and other hardware. But how about chronographs? What could we learn by setting up three different chronographs, and running a 20-shot string over all three at the same time. One of our Forum members, Randy S. (aka AAA) did that very test with three of the best chronographs you can buy: LabRadar, MagnetoSpeed, and an Oehler model 35P. The MagnetoSpeed was attached to the barrel of an F-Class rig, with the LabRadar placed on the left side of the shooting bench. The Oehler 35P was positioned about 23 feet downrange. The photo above shows the set-up. A 20-shot string was recorded with the results in a spreadsheet.

AAA talks about this interesting experiment in a Shooters’ Forum Thread. Here is his report:

Comparison Testing Three Chronographs

We all have our favorite chronograph. Each gives a number, but how would that number compare to the same round fired with another chronograph? I wanted to know so a friend and I set up the following test with three chronographs: LabRadar, MagnetoSpeed V3, and Oehler Model 35P.

For the test we fired Berger 105gr VLDs over the three chronographs simultaneously. The test rifle was my 6mm BR Ackley (BRA) F-class rig with fire-formed brass and 200 rounds on the new barrel.

Chronogaphs Tested
LabRadar
MagnetoSpeed V3
Oehler Model 35P
Temperature: 86 deg. F
Elevation: 854 feet
Cartridge: 6mm BRA (105gr Berger VLD)
Time between shots: 45 seconds

To start off, five rounds were fired to make sure all systems were recording and to warm the barrel. Then the test was 20 shots fired across all three instruments with 45 seconds between shots. The Oehler was set 7.5 yards from the muzzle so 12 FPS was added to the recorded value.

We were using the internal trigger on the LabRadar. The manual says the Vo indicated is the actual muzzle velocity when using the internal trigger, but not if using the Doppler. The 12 FPS Oehler adjustment (back to MV) was based on the Berger Ballistics Calculator.

The LabRadar Chronograph is on sale now through 12/7/2019. Buy for $499.95, a $60.00 savings.
magnetospeed chronograph test

Results of the Triple Chronograph Shoot-Out:

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

LR-M is FPS variance between LabRadar and MagnetoSpeed V3. LR-O is FPS variance between LabRadar and distance-adjusted Oehler 35P. You can see all three chronos were very consistent. ES was identical with the MagnetoSpeed and Oehler 35P, while SD was identical with the LabRadar and Oehler 35P. CLICK HERE for spreadsheet.

The tester, Randy S. (aka AAA) says: “Judge for yourself, but I was impressed by all.”

magnetospeed chronograph test
This is a manufacturer’s photo showing the Magnetospeed V3 as mounted. This is NOT the test set-up.

Comments by Forum Members
Our Forum members expressed interest in this Triple Chronograph test. Some confirmed that the LabRadar and Magnetospeed give very similar FPS numbers, based on their own tests:

“Great test and thanks for sharing. I’ve tested my MagnetoSpeed and LabRadar together and results are always within 2-4 FPS of one another.” — Big D

“Very happy to see your numbers support my decision to buy a MagnetoSpeed. Had read reports comparing it to the Oehler and the numbers I get seem to be supported by my long range shooting results. Many thanks for taking the time and effort [to perform] this comparative test. Always good to get actual test results.” — Texas10

“I did a 4-shot test with my MagnetoSpeed and another shooter’s LabRadar a couple of days ago. The results were within 4 fps with the LabRadar being optimistic.” — Pat Miles

Forum Member Powderbreak studied AAA’s original spreadsheet from the chronograph trio test, then figured out the shot-by-shot FPS variance between the machines. He concluded that all the machines performed very well. Powderbreak posted:

Analyzing the Triple Chronograph Test — What Can We Conclude?

AAA did a great job of comparing the 3 chronos. What conclusions can be drawn?

1) I have not checked the manufacturer’s claims of accuracy, but the three chronos are very close to one another. There is no way for us to determine the actual true velocities, but we do not need to do so. Any of the chronos would be more than adequate for an accurate shooter.

2) The resolution of the three chronographs is actually pretty astounding. One foot per second (FPS) is a resolution of 0.033%.

3) AAA did a great job of reloading a very consistent round. With an extreme spread of 33 fps out of 3014 for 20 rounds, that is only 1.09% total spread of velocities.

4) There is a closer velocity match between the MagnetoSpeed and the LabRadar, but that does not mean the Oehler is less accurate. There is simply an offset between the Oehler and the other two. This could be due to the greater distance, the location, or the internal working of the Oehler.

5) Believe your chronograph, it is probably the most accurate reloading tool that you own.

Brian Litz of Applied Ballistics carefully explained the operation, set-up, accuracy and comparison of AB’s chronographs in his books. [Those books] are well worth the money, and give great insight into the workings of chronographs.” — Powderbreak

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July 30th, 2019

The Affordable MagnetoSpeed Chronograph — $179.00 Sporter

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

If you have been waiting to purchase a chronograph… now is a great time to buy. You can get the affordable MagnetoSpeed Sporter for under $180.00. You can set up this device in a few minutes, and you never have to go downrange to fiddle with a tripod or fuss with wires. The MagnetoSpeed Sporter is simple and effective — a no-hassle solution.

See MagnetoSpeed Sporter Chronograph Features Reviewed in Video

We’re impressed by the Sporter chrono, as are other shooters — this unit is very popular. Like the MagnetoSpeed V3, the Sporter faithfully records shots, even in complete darkness. Shot strings are recorded digitally and can be transferred to a smart phone via MagnetoSpeed’s XFR accessory (and Apps).

The MagnetoSpeed Sporter chrono is less than half the price of previous MagnetoSpeed models. This is big news for shooters who always wanted a MagnetoSpeed but found the $379.00 cost (for V3 model) too pricey. The new Sporter Chronograph costs just $179.00 at Brownells and $179.00 at Amazon.

The Magnetospeed Sporter offers most of the features of the more expensive models (see chart below for details) and has a updated sensor. MagnetoSpeed says its new Sporter is “Ideal for contoured rifle barrels (sporter barrels) and long-barreled revolvers.” The Sporter Chronograph Kit (shown above) includes: Bayonet Sensor, 3.5 foot Data Cable, Remote Display (with Battery), Strap with thumb nut, Two V-block spacers, and compact storage box.

Available NOW: MagnetoSpeed Sporter $179.00 at Brownells and $179.00 at Amazon.

Q: Will the Sporter Chrono work with thicker barrel (i.e. greater than 1″ diameter)?

A: The manufacturer recommends the $399.00 V3 model for thicker barrels. But, wink-wink, if you have a 1.25″ barrel you can get this to work, based on what we’ve seen.. If you have a really fat barrel (up to 2.0″ diameter), get the V3. Magnetospeed also says the V3 is needed for airguns, shotguns, and muzzleloaders.

Click Image for Full-Screen Photo
magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

The Sporter Chrono attaches quickly and easily. It has a 3.5-foot-long cord, and will work with Muzzle Brakes and Flash-hiders up to 2.7″ long.

magnetospeed sporter chrono chronograph test review product speed bullet trajectory price sale

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April 11th, 2019

Velocity Test with Four Different Barrels — Surprising Results

barrel speed testing

Put the same load in a variety of barrels (with the same length and chamberings) and you’ll see a wide variance in muzzle velocity. In fact, it’s not unusual to see up to 100 fps difference from one barrel to the next. We demonstrated this with a comparison test of Lapua factory ammo.

Chron Testing Lapua Factory Ammo
At our Southern California test range some years ago, we chronographed Lapua 105gr 6mmBR factory ammo in three different 8-twist barrels of similar length. The results were fascinating. Lapua specs this ammo at 2790 fps, based on Lapua’s testing with its own 26″ test barrel. We observed a speed variance of 67 fps based on tests with three aftermarket barrels.

Barrel Velocity Variance
Brand ‘S’ and Brand ‘PN’ were pre-fit barrels shot on Savage actions. Brand ‘K’ was fitted to a custom action. All test barrels were throated for the 100-108 grain bullets, though there may have been some slight variances in barrel freebore. With a COAL of 2.330″, the rounds were “jumping” to the rifling in all barrels.

Among the four barrels, Brand ‘PN’ was the fastest at 2824 fps average — 67 fps faster than the slowest barrel. Roughly 10 fps can be attributed to the slightly longer length (27″ vs. 26″), but otherwise this particular barrel was simply faster than the rest. (Click Here for results of 6mmBR Barrel Length Velocity Test).

IMPORTANT: Results Are Barrel-Specific, Not Brand-Specific

These tests demonstrate that the exact same load can perform very differently in different barrels. We aren’t publishing the barrel-makers’ names, because it would be wrong to assume that ‘Brand X’ is always going to be faster than ‘Brand Y’ based on test results from a single barrel. In fact, velocities can vary up to 100 fps with two identical-spec barrels from the SAME manufacturer. That’s right, you can have two 8-twist, 26″ barrels, with the same land-groove configuration and contour, from the same manufacturer, and one can be much faster than another.

Don’t Demand More Than Your Barrel Can Deliver
We often hear guys lament, “I don’t get it… how can you guys get 2900 fps with your 6BRs and I can only get 2840?” The answer may simply be that the barrel is slower than average. If you have a slow barrel, you can try using more powder, but there is a good chance it may never run as fast as an inherently fast barrel. You shouldn’t knock yourself out (and over-stress your brass) trying to duplicate the velocities someone else may be getting. You need to work within the limits of your barrel.

Factory Ammo Provides a Benchmark
If you have a .223 Rem, 6mmBR, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, 6.5×55, .308 Win, 30-06, or .338 LM Rifle, we recommend you buy a box of Lapua factory-loaded ammo. This stuff will shoot great (typically around half-MOA), and it can give you a baseline to determine how your barrel stacks up speedwise. [Editor’s NOTE: The original test was conducted in 2008. The velocity of current-production Lapua factory ammo might be higher or lower, so your results may vary.]

When you complete a new 6mmBR rifle, it’s definitely smart to get a box of the factory ammo and chronograph it. That will immediately give you a good idea whether you have a slow, average, or fast barrel. Then you can set your velocity goals accordingly. For example, if the factory 6BR ammo runs about 2780-2790 fps in your gun, it has an average barrel. If it runs 2820+ in a 26″ barrel (or 2835 fps in a 28″), you’ve got a fast tube.

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March 19th, 2019

Gun Science: Engineers Plot Shots with Accelerometers

Texas Waterloo labs Youtube accelerometer gun .22 LR pistol test triangulation
A team of Texas engineers uses the principle of convolution to plot shot impacts. By triangulating data from multiple accelerometers, each shot’s exact point of impact can be plotted with great precision.

Waterloo Labs is a group of engineers from National Instruments and other self-declared “nerds” from Austin, Texas. These folks conducted an interesting demonstration using electronic accelerometers to plot bullet impacts from a suppressed Ruger MKIII .22LR pistol. The accelerometers respond to vibrations caused when the bullets hit a drywall target backer. By triangulating data from multiple accelerometers, each shot’s exact point of impact can be plotted with great precision. These point-of-impact coordinates are then fed into a computer and super-imposed into a Flash version of the Half-Life video game (which is projected on the drywall board). The end result is being able to “play” a video game with a real firearm.

triaxial accelerometerDo-It-Yourself Electronic Target System?
Now, we are NOT particularly interested in shooting Zombies in a video game. However, the technology has interesting potential applications for real shooters. Waterloo Labs has published the computer code, used to triangulate bullet impacts from multiple accelerometers. Potentially, a system like this could be built to provide display and scoring of long-range targets. Sophisticated electronic target systems already exist, but they use proprietary hardware and software, and they are very expensive. The Waterloo Labs experiment shows that shooters with some computer and electronic skills could build their own electronic scoring system, one that can be adapted to a variety of target sizes and materials.

In addition, we imagine this system could be utilized for military and law enforcement training. The walls of structures used for “live-fire” room-clearing exercises could be fitted with accelerometers so the bullet impacts could be plotted and studied. Then, later, the impact plots could be combined with a computer simulation so that trainees could “replay” their live-fire sessions, viewing the actual location of their hits (and misses).

Credit The Firearm Blog for finding this Waterloo Labs project.
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February 22nd, 2019

MV on the Box? Why You Still Need to Chron Factory Ammo

muzzle velocity applied Ballistics MV chronograph

Why You CANNOT Rely on the MV Printed on the Ammo Box!
When figuring out your come-ups with a ballistics solver or drop chart it’s “mission critical” to have an accurate muzzle velocity (MV). When shooting factory ammo, it’s tempting to use the manufacturer-provided MV which may be printed on the package. That’s not such a great idea says Bryan Litz of Applied Ballistics. Don’t rely on the MV on the box, Bryan advises — you should take out your chrono and run your own velocity tests. There are a number of reasons why the MV values on ammo packaging may be inaccurate. Below is a discussion of factory ammo MV from the Applied Ballistics Facebook Page.

Five Reasons You Cannot Trust the Velocity on a Box of Ammo:

1. You have no idea about the rifle used for the MV test.

2. You have no idea what atmospheric conditions were during testing, and yes it matters a lot.

3. You have no idea of the SD for the factory ammo, and how the manufacturer derived the MV from that SD. (Marketing plays a role here).

4. You have no idea of the precision and quality of chronograph(s) used for velocity testing.

5. You have no idea if the manufacturer used the raw velocity, or back-calculated the MV. The BC used to back track that data is also unknown.

1. The factory test rifle and your rifle are not the same. Aside from having a different chamber, and possibly barrel length some other things are important too like the barrel twist rate, and how much wear was in the barrel. Was it just recently cleaned, has it ever been cleaned? You simply don’t know anything about the rifle used in testing.

2. Temperature and Humidity conditions may be quite different (than during testing). Temperature has a physical effect on powder, which changes how it burns. Couple this with the fact that different powders can vary in temp-stability quite a bit. You just don’t know what the conditions at the time of testing were. Also a lot of factory ammunition is loaded with powder that is meter friendly. Meter friendly can often times be ball powder, which is less temperature stable than stick powder often times.

3. The ammo’s Standard Deviation (SD) is unknown. You will often notice that while MV is often listed on ammo packages, Standard Deviation (normally) is not. It is not uncommon for factory ammunition to have an SD of 18 or higher. Sometimes as high as 40+. As such is the nature of metering powder. With marketing in mind, did they pick the high, low, or average end of the SD? We really don’t know. You won’t either until you test it for yourself. For hand-loaded ammo, to be considered around 10 fps or less. Having a high SD is often the nature of metered powder and factory loads. The image below is from Modern Advancements in Long Range Shooting: Volume II.

muzzle velocity applied Ballistics MV chronograph

4. You don’t know how MV was measured. What chronograph system did the manufacturer use, and how did they back track to a muzzle velocity? A chronograph does not measure true velocity at the muzzle; it simply measures velocity at the location it is sitting. So you need to back-calculate the distance from the chrono to the end of the barrel. This calculation requires a semi-accurate BC. So whose BC was used to back track to the muzzle or did the manufacturer even do that? Did they simply print the numbers displayed by the chronograph? What kind of chronograph setup did they use? We know from our Lab Testing that not all chronographs are created equal. Without knowing what chronograph was used, you have no idea the quality of the measurement. See: Applied Ballistics Chronograph Chapter Excerpt.

5. The MV data may not be current. Does the manufacturer update that data for every lot? Or is it the same data from years ago? Some manufacturers rarely if ever re-test and update information. Some update it every lot (ABM Ammo is actually tested every single lot for 1% consistency). Without knowing this information, you could be using data for years ago.

CONCLUSION: Never use the printed MV off a box of ammo as anything more than a starting point, there are too many factors to account for. You must always either test for the MV with a chronograph, or use carefully obtained, live fire data. When you are using a Ballistic Solver such as the AB Apps or Devices integrated with AB, you need to know the MV to an accuracy down to 5 fps. The more reliable the MV number, the better your ballistics solutions.

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February 17th, 2019

Don’t Kill the Chrono! Setting up Chronos to Avoid Stray Shots

chronograph placement, shooting chrony, chrono, advisory, tech tip

There is nothing more frustrating (or embarassing) than sending a live round into your expensive new chronograph. As the photo below demonstrates, with most types of chronographs (other than the barrel-hung Magnetospeed), you can fatally injure your expensive chrono if it is not positioned precisely.

When setting up a chrono, we always unload the rifle, remove the bolt and bore-sight to ensure that the path of the bullet is not too low. When bore-sighting visually, set up the rifle securely on the sandbags and look through the bore, breech to muzzle, lining up the barrel with your aim point on the target. Then (during an appropriate cease-fire), walk behind the chronograph. Looking straight back through the “V” formed by the sky-screens, you should be able to see light at the end of the barrel if the gun is positioned correctly. You can also use an in-chamber, laser bore-sighter to confirm the visual boresighting (see photo).

Laser boresighter chronograph

Adjust the height, angle and horizontal position of the chronograph so the bullet will pass through the middle of the “V” below the plastic diffusers, no less than 5″ above the light sensors. We put tape on the front sky-screen supports to make it easier to determine the right height over the light sensors.

Use a Test Backer to Confirm Your Bullet Trajectory
You can put tape on the support rods about 6″ up from the unit. This helps you judge the correct vertical height when setting up your rifle on the bags. Another trick is to hang a sheet of paper from the rear skyscreen and then use a laser boresighter to shine a dot on the paper (with the gun planted steady front and rear). This should give you a good idea (within an inch or so) of the bullet’s actual flight path through the “V” over the light sensors. Of course, when using a laser, never look directly at the laser! Instead shine the laser away from you and see where it appears on the paper.

chronograph set-up

Alignment of Chronograph Housing
Make sure the chrono housing is parallel to the path of the bullet. Don’t worry if the unit is not parallel to the ground surface. What you want is the bullet to pass over both front and rear sensors at the same height. Don’t try to set the chrono height in reference to the lens of your scope–as it sits 1″ to 2″ above your bore axis. To avoid muzzle blast interference, set your chronograph at least 10 feet from the end of the muzzle (or the distance recommended by the manufacturer).

chronograph laser sky screens

Rifles with Elevated Iron Sights
All too often rookie AR15 shooters forget that AR sights are positioned roughly 2.4″ above the bore axis (at the top of the front sight blade). If you set your bullet pass-through point using your AR’s front sight, the bullet will actually be traveling 2.4″ lower as it goes through the chrono. That’s why we recommend bore-sighting and setting the bullet travel point about 5-8″ above the base of the sky-screen support shafts. (Or the vertical distance the chronograph maker otherwise recommends). NOTE: You can make the same mistake on a scoped rifle if the scope is set on very tall rings, so the center of the cross-hairs is much higher than the bore axis line.

Laser boresighter chronograph

TARGET AIM POINT: When doing chrono work, we suggest you shoot at a single aiming point no more than 2″ in diameter (on your target paper). Use that aiming point when aligning your chrono with your rifle’s bore. If you use a 2″ bright orange dot, you should be able to see that through the bore at 100 yards. Using a single 2″ target reduces the chance of a screen hit as you shift points of aim. If you shoot at multiple target dots, place them in a vertical line, and bore sight on the lowest dot. Always set your chron height to set safe clearance for the LOWEST target dot, and then work upwards only.

Other Chronograph Tips from Forum Members:

When using a chronograph, I put a strip of masking tape across the far end of the skyscreens about two-thirds of the way up. This gives me a good aiming or bore-sighting reference that’s well away from the pricey bits. I learned that one the hard way. — GS Arizona

A very easy and simple tool to help you set up the chronograph is a simple piece of string! Set your gun (unloaded of course) on the rest and sight your target. Tie one end of the string to the rear scope ring or mount, then pull the string along the barrel to simulate the bullet path. With the string showing the bullet’s path, you can then easily set the chronograph’s placement left/right, and up/down. This will also let you set the chrono’s tilt angle and orientation so the sensors are correctly aligned with the bullet path. — Wayne Shaw

If shooting over a chrono from the prone position off a bipod or similar, beware of the muzzle sinking as recoil causes the front of the rifle to drop. I “killed” my first chronograph shooting off a gravel covered firing point where I’d not given enough clearance to start with and an inch or two drop in the muzzle caused a bullet to clip the housing. — Laurie Holland

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December 27th, 2018

Chronos by The Numbers — Tips on ES, SD, and Sample Sizes

USAMU Marksmanship Unit Velocity Chronograph Testing Sample Sizes

The U.S. Army Marksmanship Unit (USAMU) regulary publishes “how-to” articles on the USAMU Facebook page. One informative “Handloading Hump Day” article covers chronograph testing and statistical samples. We highly recommend you read this article, which offers some important tips that can benefit any hand-loader. Visit the USAMU Facebook page next Wednesday for the next installment.

Chronograph Testing — Set-Up, Sample Sizes, and Velocity Factors

Initial Chronograph Setup
A chronograph is an instrument designed to measure bullet velocity. Typically, the bullet casts a shadow as it passes over two electronic sensors placed a given distance apart. The first screen is the “start” screen, and it triggers an internal, high-speed counter. As the bullet passes the second, or “stop” screen, the counter is stopped. Then, appropriate math of time vs. distance traveled reveals the bullet’s velocity. Most home chronographs use either 2- or 4-foot spacing between sensors. Longer spacing can add some accuracy to the system, but with high-quality chronographs, 4-foot spacing is certainly adequate.

Laboratory chronographs usually have six feet or more between sensors. Depending upon the make and model of ones chronograph, it should come with instructions on how far the “start” screen should be placed from one’s muzzle. Other details include adequate light (indoors or outdoors), light diffusers over the sensors as needed, and protecting the start screen from blast and debris such as shotgun wads, etc. When assembling a sky-screen system, the spacing between sensors must be extremely accurate to allow correct velocity readings.

Statistics: Group Sizes, Distances and Sample Sizes
How many groups should we fire, and how many shots per group? These questions are matters of judgment, to a degree. First, to best assess how ones ammunition will perform in competition, it should be test-fired at the actual distance for which it will be used. [That means] 600-yard or 1000-yard ammo should be tested at 600 and 1000 yards, respectively, if possible. It is possible to work up very accurate ammunition at 100 or 200 yards that does not perform well as ranges increase. Sometimes, a change in powder type can correct this and produce a load that really shines at longer range.

The number of shots fired per group should be realistic for the course of fire. That is, if one will be firing 10-shot strings in competition then final accuracy testing, at least, should involve 10-shot strings. These will reflect the rifles’ true capability. Knowing this will help the shooter better decide in competition whether a shot requires a sight adjustment, or if it merely struck within the normal accuracy radius of his rifle.

How many groups are needed for a valid test? Here, much depends on the precision with which one can gather the accuracy data. If shooting from a machine rest in good weather conditions, two or three 10-shot groups at full distance may be very adequate. If it’s windy, the rifle or ammunition are marginal, or the shooter is not confident in his ability to consistently fire every shot accurately, then a few more groups may give a better picture of the rifle’s true average.

(more…)

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September 27th, 2018

Gear Review: MagnetoSpeed V3 Tested by UltimateReloader

Gavin Gear Magnetospeed V3 Chronograph ultimatereloader.com

MagnetoSpeed’s technology has completely changed the market for firearms chronographs. With a MagnetoSpeed barrel-mounted chrono you can quickly and easily record muzzle velocity (MV) without having to set up tripods or walk down-range. The compact MagnetoSpeed chronos are easy to set up and transport. With the full-featured V3 model, everything you need comes in a small fitted case. In the top photo are the components used with the MagnetoSpeed V3 Kit:

1. V3 Bayonet sensor
2. Display and control unit
3. Bayonet spacers (plastic and rubber)
4. Cords and mounting hardware (left), suppressor heat shield (right)
5. Alignment rod (square cross-section)
6. Rail adapter (sold separately)

Our friend Gavin Gear of UltimateReloader.com recently reviewed the MagnetoSpeed V3 and came away impressed. Gavin explains the a good chrono is essential: “If you want to load and shoot precision ammunition, you need the tools that will produce and validate the precision of your loads. A good chronograph is one of those tools! In this post I’m going to introduce you to the MagnetoSpeed V3 chonograph, the high-end electromagnetic chronograph which fills out the top slot in MagnetoSpeed’s equipment portfolio.”

In this 11-minute video Gavin reviews MagnetoSpeed’s top-of-the-line V3 Chronograph. He shows what ships with the unit, how to set it up for both rifles and pistols, and then he puts it through its paces showing how it captures velocity data. Gavin says he will follow-up with future videos showing how to link the MagnetoSpeed V3 to your mobile phone and how to log velocity data for future reference. To learn more about this high-tech chrono, visit UltimateReloader.com.

READ Full MagnetoSpeed V3 Review on UltimateReloader.com »

Gavin Gear Magnetospeed V3 Chronograph ultimatereloader.com

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July 16th, 2018

New Mobile App for LabRadar Chronograph

LabRadar chronograph doppler mobile app android apple ios firmware update

Love your LabRadar chronograph? Or wish you owned one? Well now the LabRadar is even better. The makers of the advanced, Doppler-radar LabRadar system have introduced a versatile new LabRadar Mobile App that works with iOS (Apple) and Android systems.

The Mobile App lets you control the LabRadar remotely with your smartphone or laptop. This makes it easier when you position the LabRadar beyond arms reach (such as when using a suppressor). The App also makes it much easier and faster to change settings, display shot data, and download test results.

LabRadar Android Mobile App:
LabRadar chronograph doppler mobile app android apple ios firmware update

Initial feedback on the LabRadar Mobile App has been very positive, though it took some guys a couple tries to get everything working right. Android users — be sure to turn on your “Location Services”. You’ll find a full discussion of the LabRadar App, with set-up tips, on our Shooters’ Forum. Read HERE.

LabRadar iOS (Apple) App, iPad Version:
LabRadar chronograph doppler mobile app android applie ios firmware update

Here’s a recent review from a LabRadar owner using an Android phone: “[This App] makes the LabRadar exponentially more useful without additional cost. Firmware update to 1.20 was uneventful and quick. No issues running this on a Samsung Galaxy S9+. Shot series can be reviewed on the phone while disconnected from the radar. While connected you can change the radar settings from within the App. Great features and flawless execution.”

LabRadar Mobile App Functionality
With the new Mobile App, you can control your Labradar from your smartphone or tablet with its Bluetooth connection. Manage, store or delete the information in your series as you wish. View your data and summaries displayed in list or table formats. Even view a graph of speed vs. distance.

– Control your LabRadar from your smartphone or tablet
— Display Single Shot Stats: Velocity, Energy, Power Factor
— Display Shot Series Stats: Average, ES, SD, Hi/Lo Shot
— View Velocity by Distance as Graph and List
— Arm, disarm, and change your settings

How to Install and Use LabRadar Mobile App

First get the LabRadar App for your mobile device. Download the Android App from Google Play. Get the iOS (Apple) Version from the Apple App Store. You may also need to update your LabRadar Firmware.

labradar mobile app android google play labradar mobile app apple Ios

Firmware Update to Enable Bluetooth
LabRadar owners may need to upgrade their chrono’s Firmware to allow the unit to communicate with the Mobile App. The latest firmware will enable the Bluetooth connectivity on your LabRadar device. Download the new Firmware v1.2.2 by following the link below.

1. Go to http://www.mylabradar.com/download/
2. Select: Labradar Firmware v1.2.2 (English) Mobile App Ready.
3. Copy the FWA and FWB files to a SD card (or use the USB cable method).
4. Insert the SD card in your Labradar and turn it on.
5. On your Android Device, make sure your location services is enabled.
6. IMPORTANT — Do NOT PAIR your Bluetooth device to the Labradar! When using the mobile App simply connect to your Labradar from within the App.

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June 20th, 2018

Chrono Comparison Test: LabRadar, Magnetospeed, & Oehler 35P

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

We see comparison tests of cars, cameras, and other hardware. But how about chronographs? What could we learn by setting up three different chronographs, and running a 20-shot string over all three at the same time. One of our Forum members, Randy S. (aka AAA) did that very test with three of the best chronographs you can buy: LabRadar, MagnetoSpeed, and an Oehler model 35P. The MagnetoSpeed was attached to the barrel of an F-Class rig, with the LabRadar placed on the left side of the shooting bench. The Oehler 35P was positioned about 23 feet downrange. The photo above shows the set-up. A 20-shot string was recorded with the results in a spreadsheet.

AAA talks about this interesting experiment in a Shooters’ Forum Thread. Here is his report:

Comparison Testing Three Chronographs

We all have our favorite chronograph. Each gives a number, but how would that number compare to the same round fired with another chronograph? I wanted to know so a friend and I set up the following test with three chronographs: LabRadar, MagnetoSpeed V3, and Oehler Model 35P.

For the test we fired Berger 105gr VLDs over the three chronographs simultaneously. The test rifle was my 6mm BR Ackley (BRA) F-class rig with fire-formed brass and 200 rounds on the new barrel.

Chronogaphs Tested
LabRadar
MagnetoSpeed V3
Oehler Model 35P
Temperature: 86 deg. F
Elevation: 854 feet
Cartridge: 6mm BRA (105gr Berger VLD)
Time between shots: 45 seconds

To start off, five rounds were fired to make sure all systems were recording and to warm the barrel. Then the test was 20 shots fired across all three instruments with 45 seconds between shots. The Oehler was set 7.5 yards from the muzzle so 12 FPS was added to the recorded value.

We were using the internal trigger on the LabRadar. The manual says the Vo indicated is the actual muzzle velocity when using the internal trigger, but not if using the Doppler. The 12 FPS Oehler adjustment (back to MV) was based on the Berger Ballistics Calculator.

Results of the Triple Chronograph Shoot-Out:

labradar chronograph test magnetospeed V3 oehler 35P 6mmBR Ackley BRA

LR-M is FPS variance between LabRadar and MagnetoSpeed V3. LR-O is FPS variance between LabRadar and distance-adjusted Oehler 35P. You can see all three chronos were very consistent. SD was identical with the LabRadar and MagnetoSpeed. CLICK HERE for spreadsheet.

The tester, Randy S. (aka AAA) says: “Judge for yourself, but I was impressed by all.”

Comments by Forum Members
Our Forum members expressed interest in this Triple Chronograph test. Some confirmed that the LabRadar and Magnetospeed give very similar FPS numbers, based on their own tests:

“Great test and thanks for sharing. I’ve tested my MagnetoSpeed and LabRadar together and results are always within 2-4 FPS of one another.” — Big D

“Very happy to see your numbers support my decision to buy a MagnetoSpeed. Had read reports comparing it to the Oehler and the numbers I get seem to be supported by my long range shooting results. Many thanks for taking the time and effort [to perform] this comparative test. Always good to get actual test results.” — Texas10

“I did a 4-shot test with my MagnetoSpeed and another shooter’s LabRadar a couple of days ago. The results were within 4 fps with the LabRadar being optimistic.” — Pat Miles

Forum Member Powderbreak studied AAA’s original spreadsheet from the chronograph trio test, then figured out the shot-by-shot FPS variance between the machines. He concluded that all the machines performed very well. Powderbreak posted:

Analyzing the Triple Chronograph Test — What Can We Conclude?

AAA did a great job of comparing the 3 chronos. What conclusions can be drawn?

1) I have not checked the manufacturer’s claims of accuracy, but the three chronos are very close to one another. There is no way for us to determine the actual true velocities, but we do not need to do so. Any of the chronos would be more than adequate for an accurate shooter.

2) The resolution of the three chronographs is actually pretty astounding. One foot per second (FPS) is a resolution of 0.033%.

3) AAA did a great job of reloading a very consistent round. With an extreme spread of 33 fps out of 3014 for 20 rounds, that is only 1.09% total spread of velocities.

4) There is a closer velocity match between the MagnetoSpeed and the LabRadar, but that does not mean the Oehler is less accurate. There is simply an offset between the Oehler and the other two. This could be due to the greater distance, the location, or the internal working of the Oehler.

5) Believe your chronograph, it is probably the most accurate reloading tool that you own.

Brian Litz of Applied Ballistics carefully explained the operation, set-up, accuracy and comparison of AB’s chronographs in his books. [Those books] are well worth the money, and give great insight into the workings of chronographs.” — Powderbreak

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