by Sierra Bullets Ballistic Technician Paul Box This cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.
This cartridge was far ahead of its time and for that reason it received a lot of bad press. We’ve all read the horror stories through the years. Many of those stories were just simply repeated from previous articles even the wording was just slightly different. So how bad was the Swift? Let’s take a deeper look.
Some of the early Swifts had soft barrel steel and some of the rare ones even had barrels that were .223 in bore size. This stemmed from the fact that the .22 Hornets prior to the end of World War II were .223 in bore size and some of these barrels were chambered in the Swift. It was rumored that the Swift peaked in pressure far too quick. I’ll bet they did with a turkey extra full choke barrel.
Burn rates of powders were limited at that time as well, so the Swift was limited in its true ability due to that. It was almost like building a funny car for drag racing when only kerosene was available.
One of the longest lasting black eyes was that it shot barrels out so fast. If you get the barrel branding iron hot and fail to clean it often this can happen. Common sense will go a long ways here. Keep the barrel as cool as you can and properly clean it every fifteen rounds or less will go a long way to improving accuracy life of a Swift.
So what is the real truth about this cartridge? I’m glad you ask. I’ve been shooting the .220 Swift for over 43 years now. It is one of the best varmint cartridges I’ve ever owned. It is not hard to load for, it doesn’t suddenly peak in pressure and it isn’t the barrel burner that you’ve heard. Hodgdon powders once reported a Remington 40-X with over 3,000 rounds of full power loads averaged .344” for five, 5-shot groups. My findings have been the same. It isn’t as hard on barrels as it has been made out to be.
I’ve also read that down loading it slightly will help in barrel life. This is true, but if you buy a thoroughbred you want him to run. Barrels are threaded on the end for a reason. If you have enough fun to shoot out a Swift barrel, just rebarrel it.
The bottom line is enjoy the .220 Swift for what it was meant to be. The popularity of the Swift has slipped in the last twenty years and few factory rifles are now available in this caliber. There is no reason for this and I know the Swift will always have a strong and loyal following.
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PMA Tool offers lightweight yet sturdy cleaning cradles that are handy, affordable, and easy to transport. PMA’s popular single-gun cradle, priced at $99.95, is ideal for benchrest and F-Class rigs. It measures about 17″ in length and weighs about one pound. You can choose among 2.25″, 3″, 4″, 5″, and 6″-wide saddles (U-shaped padded supports) to match your forearm width.
PMA also offers an excellent double cradles for $149.95. These twin cradles have 2.5″, 3″, or 4″ saddles, or a combo of 3″ / 2.25″ front saddles. All these cradle types secure your rifle(s) in a muzzle-down position that allows easy cleaning and prevents solvents from running back into the action. The front saddles and all contact surfaces are covered by thick silicone rubber padding which grips the rifle securely yet protects the stock and components from scratches.
These cradles are most commonly sold with a 3″-wide front saddle for Benchrest and F-Open style stocks, or a 2.25″-wide front saddle for rifles with narrower fore-ends such as those found on F-TR, Hunter Class, and varmint stocks. In addition, you can get 4″-wide, 5″-wide, and even 6″-wide saddles for the big, long range benchrest rifles.
Double Rifle Cradle is a Smart, Versatile Design
PMA’s double rifle cleaning cradle was was designed from the ground up to work perfectly for two rifles side-by-side. Using the same tie bar and protective saddles found on the single cradel, PMA widened the base and created new uprights to support the saddles, making the cradle as narrow and light as possible, while retaining all the protective and non-slip features from our single unit.
This PMA Tool double cradle unit is available with twin 3″ front saddles, double 2.5″ front saddles or combination 3″ / 2.25″ front saddle configurations to accommodate different classes of benchrest rifles.
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Coalinga Range in California. At dawn we could clearly see 7mm and .30 Cal bullet holes at 1000 yards.
While attending the CA Long Range Championship a few seasons back, we had the opportunity to test the performance of a high-magnification (63X) spotting scope in near-ideal conditions (maybe the best I’ve ever witnessed). On the event’s last day we arrived at 5:45 am, literally as the sun was cresting the horizon. I quickly deployed our Pentax PF-100ED spotting scope, fitted with a Pentax SMC-XW 10mm fixed-power eyepiece. When used with the 100mm Pentax scope, this 10mm eyepiece yields 63X magnification. Befitting its $299.00 price, this eyepiece is extremely clear and sharp.
At the crack of dawn, viewing conditions were ideal. No mist, no mirage, no wind. The first thing this Editor noticed was that I could see metal nail heads on the target boards. That was astonishing. As soon as the first practice targets went up, to my surprise, I could see 6.5mm, 7mm, and 30-caliber bullet holes in the white at 1000 yards. No lie…
That’s right, I could see bullet holes at 1000. I know many of you folks may not believe that, but there was no mistaking when I saw a 7mm bullet cut the white line separating the Nine Ring and Eight Ring on the target in view. (I was watching that target as the shot was fired and saw the shot-hole form). And when I looked at the 30-cal targets, the bullet holes in the white were quite visible. In these perfect conditions I could also make out 3/8″ bolt heads on the target frames.
The Human Factor — Good Vision Required
When viewing the bullet holes, I was using my left naked eye (no safety glasses or magnification). I also had a contact lens in my right eye (needed for distance vision). To my surprise, while I could see the bullet holes without much difficulty with my left eye, things were fuzzier and slightly more blurry with the right eye, even when I re-focused the scope. That contact lens was degrading the fine resolution.
Then I invited 3 or 4 shooters to look through the scope. One younger guy, with good eyes, said immediately: “Yeah, I can see the holes — right there at 4 o’clock and seven o’clock. Wow.” Some older guys, who were wearing glasses, could not see the holes at all, no matter what we did to the scope’s main focus and diopter adjustment.
The lesson here — if you have to wear glasses or corrective contact lenses, just that extra bit of optical interference may make a difference in what you can see through the scope. Basically anything that goes between the scope eyepiece and your eyeball can degrade the image somewhat. So… you may be better off removing your glasses if you can still obtain good focus sharpness using the diopter adjustment and focus ring. I did the left vs. right eye test a half dozen times, and I could definitely see small features at 1000 yards with my naked eye that I could not see with my right eye fitted with a contact lens. (I did have to re-focus the scope for each eye, since one had a corrective lens while the other did not.)
Mirage Degrades Image Sharpness and Resolution
The “magic light” prevailed for only an hour or so, and then we started to get some mirage. As soon as the mirage appeared I was no longer able to see raw bullet holes, though I could still easily see black pasters on the black bulls. When the mirage started, the sharpness of the visible image degraded a huge amount. Where I could see bullet holes at dawn, by mid-morning I could barely read the numbers on the scoring rings. Lesson: If you want to test the ultimate resolution of your optics, you need perfect conditions.
Chromatic Aberration Revealed
As the light got brighter and the mirage increased I started to see blue and red fringing at the edges of the spotting disk and the large numerals. This was quite noticeable. On one side of the bright, white spotting disc you could see a dark red edge, while on the other side there was a blue edge (harder to see but still present).
The photo below was taken through the Pentax spotter lens using a point and shoot camera held up to the eyepiece. The sharpness of the Pentax was actually much better than this photo shows, but the through-the-lens image does clearly reveal the red and blue fringing. This fringing is caused by chromatic aberration — the failure of a lens to focus all colors to the same point. Chromatic aberration, most visible at high magnification, causes different wavelengths of light to have differing focal lengths (see diagram). Chromatic aberration manifests itself as “fringes” of color along boundaries that separate dark and bright parts of the image, because each color in the optical spectrum cannot be focused at a single common point on the optical axis. Keep in mind that the Pentax does have “ED” or low-dispersion glass, so the effect would be even more dramatic with a cheaper spotting scope.
If you wonder why top-of-the-line spotting scopes (such as the $3470 Swarovski ATS-80 ) cost so much, the answer is that they will deliver even LESS chromatic aberration at long range and high magnification. With their exotic apochromatic (APO), ultra-low-dispersion glass, a few ultra-high-end spotting scopes can deliver an image without the color edging you see in the photo above.
The Pentax PF-100ED is a heck of a spotting scope. Any scope that can resolve bullet holes at 1000 yards is impressive. But if you want the ultimate in optical performance, with minimal chromatic aberration, you may need to step up to something like the 88mm Kowa Prominar TSN-88A Prominar with Flourite Crystal lenses ($3699.00 with 25-60X eyepiece), or the 82mm Leica APO ($3598.00 with 25-50X eyepiece).
EDITOR’s NOTE: The purpose of this report is to show what is possible… in IDEAL conditions. With this Pentax 100mm, as well as a Swarovski 80mm, we can often resolve 6mm bullet holes at 600 yards. But again, that performance requires really good viewing conditions. By 10:00 am at my range, even with the 100mm Pentax at 75 power, seeing 6mm bullet holes is “iffy” at best. So don’t go out and mortgage the house to buy a $4000 optic with the hope that you’ll be able to spot your shots at 1000 yards. If conditions are anything less than perfect, you’ll be lucky to see bullet holes at 500 yards.
The real solution for very long-range spotting is to set up a remote target cam that broadcasts a video picture to a screen at your shooting station. Among the target cams on the market, we recommend the LongShot LR-3 2-mile UHD. This modern target cam system boasts excellent resolution and incredible range. The LongShot LR-3 target cam is used in major ELR competitions. The Longshot LR-3 currently sells for $899.00 on Amazon.
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Credit our buddy Joe Friedrich for this simple yet effective accessory for your benchrest rifle. Joe shoots a .22 LR benchrest rig with a barrel tuner. When he added weights to his tuner, he found his rifle no longer balanced well. He wanted to add some weight in the rear without drilling holes in the stock. He also wanted the weight to be removable, and easily placed on another rifle in his stable. He wanted a weight that could be moved from gun to gun as needed.
At a local sporting goods shop Joe found a 1.5-lb ankle weight that comes in a padded, tubular elastic cover. It’s like a 1.5-lb sausage in a soft, stretchy nylon cover. (Imagine a really fat, heavy bungee cord). Joe simply attached a plastic zip tie at the end to make a loop that fits perfectly over his buttstock. CLICK HERE for full-screen photo.
To “tune” the rifle’s balance, Joe just slides the ankle weight fore and aft on the stock. We have tried this moveable ankle weight on a variety of different BR stocks (including a McMillan Edge) and it worked perfectly. This is a great invention, and would work with sporter rifles and ARs just as well.
NOTE: Obviously, this ring will increase the measured weight of your rifle. So, if you are competing in a registered match with weight restrictions, you have to ensure that your rifle still makes class weight limits with the ankle weight ring in place.
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From time to time, we all encounter a primer that doesn’t go off. It’s normal to attribute the problem to a bad primer. But sometimes there are other explanations. George S., one of our Forum members, experienced a couple failures to fire, but he learned that the issue was his priming TOOL, not his primers. Here’s what George told us. There’s a lesson to be learned:
“I had issues with CCI 450s when I had my first 6BR barreled. I had probably three or four out of 20 rounds that failed to fire. the primers were dented but didn’t fire. I called CCI since I had bought a case of them. The tech was decent enough but had the audacity to tell me I was not seating the primers all the way in the pocket. I proceeded to let him know I had been reloading longer than he had been alive and I knew how to seat a primer.
Turns out that I did and I didn’t! I was using the RCBS primer tool I had used for years and the primers felt just fine to me. I finally decided to check the tool and since I had a new one I took the seating pins out and measured them. The seating pin on the tool I had been using for years was shorter by a few thousandths! I then used the pin from the new primer tool and darned if the primers that didn’t seat down to the bottom of the cup.
I switched to a K&M primer tool for seating the CCI primers and have not had a problem since. It was the combination of harder cup and lack of proper seating. I did call the CCI tech back and apologized for being an idiot.”
Another Forum member witnessed a problem cause by misuse of a priming tool: “I did … see a failure to fire on a Rem 9 1/2 primer only a week ago. That was in the new Rem muzzleloader that uses a primed case to ignite the pellets. After watching the muzzleloader’s owner seat his primers, I believe that it was operator error not the primer. He was seating the primer and then squeezing the priming tool so hard that his hands hurt after a few. We got that corrected.”
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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.”
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 find the article(s) you want in the list. For each selection, then click “Download” in the right column. This will send a PDF version to your device.
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Are you a do-it-yourself kind of guy with a creative eye? Then you’ll love the FREE Target Generator from the folks at ShooterShed.com. This FREE, interactive webpage allows you to design a variety of fun targets, including grids, benchrest-type Score/Group Shooting targets, sight-in targets, and even playing card targets. Choose the paper size and orientation (vertical or horizontal), then select the number of target elements on the page. For example, you could have four (4) bulls or a dozen playing cards. Then click the Style TAB to choose your target style. Use the OPTIONS TAB to overlay a grid on the target, choose squares or diamonds, or include load information blocks. For bullseye targets, you can control the number, color, and spacing (diameter) of the rings. LINK to TARGET GENERATOR.
QWIK TIP: For Super-Quick Target Creation, click the “Target Style” tab, then select a design from the list on the left. Then go to OPTIONS.
Click the TARGET STYLE TAB to select one of many target styles, including NBRSA Benchrest targets and 20+ types of NRA bullseye targets, scaled to distance:
Benchrest
Bullseye
Shapes
NRA High Power
NRA Pistol
NRA Rimfire
Images
Playing Cards
Load Test Blocks
Creating new targets is fast and easy. No computer graphics skills required! We created this green diamonds grid target in just five minutes using the ShooterShed Target Generator:
And here is a handy target with short-range range Benchrest competition-style box/circle aiming points, along with fields for entry of gun/load data:
The program provides a preview of each target you generate. There are controls to choose border and fill colors. If you like a particular design, save the file, and then print as many targets as you want. Check it out, this program is fun and handy to use. Here are four (4) targets your Editor created just for this article. With a bit of practice, you can be generating your own custom targets in minutes.
About the Creator of the Target Generator
The Target Generator program was created by Rod Brown of Sheridan, Wyoming. Rod tells us: “I build custom rifles… I’ve got a 100-yard range out my back door. I shoot short- and long-range benchrest competitively around the country. I’m a full-time software development consultant and an FFL holder. When I’m not developing custom software for my clients, I’m usually fiddling in the shop, building a custom benchrest rifle, traveling to a match, chambering a barrel, or reloading some ammunition.”
Story tip from Boyd Allen. We welcome reader submissions.
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The 17 Mach 2 (aka “17 HM2″) is making a come-back. We’re glad. This high-velocity round fits actions and magazines designed for the .22 LR, so it’s an easy barrel-swap upgrade for most rimfire bolt-guns (semi-autos are more complicated). The 17 Mach 2 cartridge doesn’t deliver the velocity of the 17 HMR, but it is still way faster than a .22 LR. Expect 2000-2100 fps with 17 Mach 2 compared to 1250 fps for “High-Velocity” .22 LR ammo. And, importantly, 17 Mach 2 ammo is much less expensive than 17 HMR. If you shop around, you can get 50 rounds of 17 Mach 2 for about $8.50. That’s 43% cheaper than a better-than-average* $14.99 price of 17 HMR — a significant savings at 17 cents/round vs. 30 cents/round!
17 Mach 2 Major Selling Points:
1. 60% more velocity than typical “High-Velocity” .22 LR ammo.
2. 40% less cost than average 17 HMR ammo.
3. 17 Mach 2 OAL is compatible with .22 LR receivers and magazines.
17 Mach 2 — Best High Velocity Rimfire Bang for the Buck?
If you are looking for a capable, squirrel-busting round or a fun plinking round, you should definitely consider the 17 Mach 2, especially since CCI has committed to production of the little cartridge. CCI recently rolled out its “Gen 2″ 17 Mach 2 VNT Ammo with polymer tip (see top of article).
Considering that 17 HMR ammo is typically $15 to $17 per box, the 17 Mach 2 is a good value by comparison. It is available from vendors for about $8.50 per 50ct box. That’s $0.17 per round. When you consider overall “bang for the buck”, for many shooters, it makes sense to use the 17 Mach 2 rather than a 17 HMR. You save money, barrel life is a little longer, and the 17 Mach 2 is still a much more potent cartridge than the .22 LR. Check out this comparison, and note how the 17 Mach 2 has a much flatter trajectory than the .22 LR. For varmint shooting, the 17 Mach 2 is clearly the better choice.
And you can easily adapt a .22 LR Rifle to shoot the 17 Mach 2 just by changing the barrel. The magazine and bolt operation should work as the cartridge length, cartridge body diameter, and rim size is the same as the .22 LR.
Hornady’s 17 Mach 2 has a 2100 FPS muzzle velocity vs. 1255 FPS for “High-Velocity” .22 LR.
17 Mach 2 Rifle Reviews
Gun-makers have taken notice of the availability of 17 Mach 2 ammo, introducing new models chambered for this versatile little rimfire round. For a high-volume, small-species varminting, the 17 Mach 2 is much more effective than the .22 LR, and much less expensive than the larger 17 HMR.
New Savage A17 in 17 Mach 2
There are a number of reviews on new-generation 17 Mach 2 rifles. Recently Varminter.com reviewed the Savage A17 in 17 HM2. Editor Eric Mayer wrote: “This new addition to the A17 line comes at a time when the 17 Mach 2 round is experiencing a resurgence, with ammo now available from CCI and Hornady, including the lead-free NTX round from Hornady. This means … you don’t have to break the bank to buy a current, functioning, semi-auto 17 Mach 2 and you don’t have to … convert your 10/22.”
Eric shot four different types of 17 Mach 2 ammo, putting 1000+ rounds through the Savage. He was impressed: “I am very excited that Savage Arms has chambered their A17 rifle in the 17 Mach 2 / 17 HM2 round. After shooting the prototype, I can confidently say that this new A17 will become my go-to 17 Mach 2 rifle. This new rifle is a great option for varminters everywhere!”
Toggle Bolt Volquartsen Summit in 17 HM2
It’s rare for us to see a new rimfire that we’d really like to own, but the new Summit from Volquartsen fits the bill. This versatile rifle features a cool, straight-pull toggle bolt, similar to those on elite Biathlon rifles. You can see how this gun shoots in this informative 22 Plinkster video:
22 Plinkster Tests Volquartsen Summit Rifle in 17 Mach 2
The 17 Mach 2 (17 HM2) is making a comeback. Now leading manufacturers are offering this efficient little rimfire cartridge in some nice rifles. Both Anschutz and Volquartsen will offer new 17 Mach 2 rifles in 2019. The Volquartsen Summit features a lightweight, carbon fiber-wrapped barrel threaded 1/2-28 for brakes or suppressors. The Summit boasts a nice 1.75-lb trigger pull. The Summit’s CNC-machined receiver features a +20 MOA Rail. NOTE: The video shows a silhouette-style laminated wood stock. However, the Summit comes standard with a composite Magpul stock that actually works better for shooting from a bench.
*Note: The cheapest 17 HMR we found via nationwide search was $12.50/box, but MidwayUSA charges $19.99 for 50 rounds of most 17 HMR types. At most vendors you’ll pay $16-$18 per box for 17 HMR ammo.
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“The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.” — William Arthur Ward
Readers often ask us: “Is there a decent, easy-to-comprehend book that can help my wind-reading?” Many of our Forum members have recommended The Wind Book for Rifle Shooters by Linda Miller and Keith Cunningham.
New Edition — Hardback and eBook
The latest, updated edition of The Wind Book for Rifle Shooters was released in May 2020. This 144-page book, first published in 2007, is a great resource. But you don’t have to take our word for it. If you click this link, you can read book excerpts and decide for yourself. When the Amazon page opens, look below the book cover photo, and click the bar labeled “Read Sample”. This lets you preview chapters from the Wind Book, and view some illustrations. Along with the hardback edition ($22.99), Amazon offers a Kindle (eBook) edition for $14.99.
Other books cover wind reading in a broader discussion of ballistics or long-range shooting, such as Applied Ballistics for Long-Range Shooting by Bryan Litz. But the Miller & Cunningham book is ALL about wind reading from cover to cover, and that is its strength. The book focuses on real world skills that can help you accurately gauge wind angle, wind velocity, and wind cycles.
All other factors being equal, it is your ability to read the wind that will make the most difference in your shooting accuracy. The better you understand the behavior of the wind, the better you will understand the behavior of your bullet. — The Wind Book for Rifle Shooters
The Wind Book for Rifle Shooters covers techniques and tactics used by expert wind-readers. There are numerous charts and illustrations. The authors show you how to put together a simple wind-reading “toolbox” for calculating wind speed, direction, deflection and drift. Then they explain how to use these tools to read flags and mirage, record and interpret your observations, and time your shots to compensate for wind.
I believe this is a must-have book if you are a long-range sport shooter. I compete in F-Class Open and when I first purchased this book and read it from cover to cover, it helped me understand wind reading and making accurate scope corrections. Buy this book, read it, put into practice what it tells you, you will not be disappointed. — P. Janzso
If you have one book for wind reading, this should be it. Whether you’re a novice or experienced wind shooter this book has something for you. It covers how to get wind speed and direction from flags, mirage, and natural phenomenon. In my opinion this is the best book for learning to read wind speed and direction. — Muddler
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As does Lapua and some other leading bullet-makers, Barnes now uses radar to determine bullet BC values and ballistic data for its match bullets and ammunition. Barnes employs advanced Doppler Radar to record bullet speeds at multiple distances out to 1500 yards.
The Doppler radar system gathers thousands of data points as a bullet flies downrange. This radar data is used to generate a bullet specific drag curve, and then fed into a modern 6 Degree of Freedom (DOF) [ballistics software program] to generate precise firing solutions.
Determining Bullet Ballistics with Doppler Radar Data
How do you build better (more precise) ammo drop tables? With radar, that’s how. Barnes Bullets is using Doppler Radar to develop the drop tables for its Precision Match line of factory ammunition. The Doppler radar allows Barnes to determine actual velocities at hundreds of points along a bullet’s flight path. This provides a more complete view of the ballistics “behavior” of the bullet, particularly at long range. Using Doppler radar, Barnes has learned that neither the G1 nor G7 BC models are perfect. Barnes essentially builds a custom drag curve for each bullet using Doppler radar findings.
Use of Doppler Radar to Generate Trajectory Solutions
by Barnes Bullets, LLC
Typical trajectory tables are generated by measuring only two values: muzzle velocity, and either time-of-flight to a downrange target, or a second downrange velocity. Depending on the test facility where this data is gathered, that downrange target or chronograph may only be 100 to 300 yards from the muzzle. These values are used to calculate the Ballistic Coefficient (BC value) of the bullet, and the BC value is then referenced to a standardized drag curve such as G1 or G7 to generate the trajectory table.
This approach works reasonably well for the distances encountered in most hunting and target shooting conditions, but breaks down rapidly for long range work. It’s really an archaic approach based on artillery firings conducted in the late 1800s and computational techniques developed before the advent of modern computers.
There is a better approach which has been utilized by modern militaries around the world for many years to generate very precise firing solutions. Due to the sizeable investment required, it has been slow to make its way into the commercial market. This modern approach is to use a Doppler radar system to gather thousands of data points as a bullet flies downrange. This radar data is used to generate a bullet specific drag curve, and then fed into a modern 6 Degree of Freedom (DOF) [ballistics software program] to generate precise firing solutions and greatly increase first-round hit probability. (The 6 DOF software accounts for x, y, and z position along with the bullet’s pitch, yaw, and roll rates.)
Bullet-Specific Drag Curves Derived from Radar Data
Barnes’ advanced Doppler radar system can track bullets out to 1500 meters, recording the velocity and time of flight of that bullet every few feet along the flight path. The noteworthy graph below shows a Doppler Radar-derived, bullet-specific drag curve alongside the more common G1 and G7 curves:
Neither of the standard curves is a particularly good match to our test bullet. In the legacy approach to generating a downrange trajectory table, the BC value is in effect a multiplier or a fudge factor that’s used to shift the drag curve of the test bullet to try and approximate one of the standard curves. This leads to heated arguments as to which of the standardized drag curves is a better fit, or if multiple BC values should be used to better approximate the standard curve (e.g., use one BC value when the velocity is between Mach 1 and Mach 2, and a different BC value when the velocity is between Mach 2 and Mach 3.) Barnes’ approach to creating trajectory tables is to generate bullet-specific drag curves, and use that data directly in a modern, state-of-the-art, 6 DOF ballistics program called Prodas to generate the firing solution.
Story tip from EdLongrange. We welcome reader submissions.
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The Applied Ballistics Facebook Page features great, interesting new content posted multiple times each week. This resource features videos, test results, accuracy tips, and samples from Bryan Litz’s excellent books on ballistics and the three volume series on Modern Advancements in Long Range Shooting. Here are some highlights from Applied Ballistics’ Facebook posts from the past two weeks. Plus there’s a discount code, READ2024, that can save you 25% on Applied Ballistics books purchased in the month of March.
.22 LR Super Slow Motion Video — Watch the Bullet!
Watch .22 LR Rimfire Projectile Exiting Rifle Muzzle
This video, filmed with an ultra-high-speed camera, shows the milliseconds in time as a .22-caliber bullet travels the first 11 inches after leaving a .22 LR rifle barrel. Applied Ballistics states: “Notice that the bullet is fully obturated to the internal bore dimension — the step/rebate that exists on the unfired bullet where it meets the case gets expanded (obturated) and doesn’t exist on the fired bullet.”
How Important is Case Fill Ratio — You May Be Surprised
Conventional reloading practice is to select a powder that gives you a good case fill, meaning 90%-100% fill ratio for the cartridge and bullet you’re using. But why?
Some say that a higher fill ratio is good because it prevents the powder from settling differently in the case (which could lead to inconsistent ignition and greater MV SD). This explanation sounds good, and went unchallenged for a long time. However, Applied Ballistics has done some interesting testing that sheds new light on the density issue.
Modern Advancements in Long Range Shooting – Vol. 2 contains the results of Applied Ballistics tests of five different cartridge types — .223 Rem to .338 Lapua — loaded with different powders to produce fill ratios of 80%, 90%, and 100%. The testers wanted to see if 100% fill ratios actually gave better results (lower MV SDs) than the lower fill ratios.
Results of testing 3 different loads in 5 different cartridges — The highest MV SD was in fact measured in an 80% fill ratio load. However, the lowest MV SD was also measured for a different 80% load! Seems like the more we learn, the more questions we have. An informative Applied Ballistics podcast covers the Fill Ratio test. Visit Thescienceofaccuracy.com to access this and interesting podcasts.
EDITOR’s NOTE: There were multiple comments from Facebook readers stating that fill ratios 90% and above worked more consistently for them. And the reloading manuals warn against very low fill ratios.
Get 25% Off Applied Ballistics Books in March 2024
Applied Ballistics, through its Science of Accuracy webstore, is currently offering big savings on its popular books — considered to be the best print resources about rifle accuracy/ballistics ever published. This month you can save 25% on all six Applied Ballistics book titles by respected expert (and past national champion) Bryan Litz. Use Code READ2024 to get 25% of one or more of these books.
Get 25% OFF Applied Ballistics Books! Use code: READ2024 at checkout.
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Americans love AR-platform rifles. However, they can be maintenance-intensive, as hot gasses are directed right back into the action to operate the bolt. Because ARs have a somewhat unique (and dirty) semi-auto operating system, we think all AR owners should learn how their rifles operate — from the inside out. This feature provides an “inside look” at the AR, with X-Ray and Cutaway views created through advanced 3D computer modeling.
AR15 Functions Revealed with 3D Computer Animation
Ever wondered how the parts inside an AR15 work together? Just exactly how does the reciprocating bolt carrier feed rounds from the magazine? How do the elements in the trigger group work and reset after each shot? How does the gas system bleed gas from the barrel and operate the bolt carrier? These and other questions are answered in this eye-opening video from 45Snipers. Using “cutaway” 3D computer animation, this 5-minute video shows all features of an AR15 inside and out. This fascinating firearms animation allows the viewer to look inside the upper and lower receivers, into the bolt carrier, chamber, barrel, and magazine.
This video starts off slow and has annoying background music, but it is well worth watching if you own or shoot any AR-platform rifle. It illustrates all the key operations during the charging, loading, firing, and ejection processes. The cutaway animation shows how rounds are stripped from the magazine and then chambered. It then shows how every part of the trigger group works, and how the firing pin strikes the primer. You can even watch the bullet move down the barrel before the empty shell casing is removed from the chamber and tossed out the ejection port. Here are sample frames from the video:
How AR-Platform Rifles Work — General Introduction
To help reader understand the general operation of AR-type rifles, this video shows the control functions of an AR and how the upper and lower sections work together.
Cutaway 3D Animation of AR15/M16 Action — Watch Video
Here is an excellent “cutaway” animation by Thomas Schwenke that shows how an AR-15 functions — how the entire loading cycle works from start to finish.
AR platform rifles are semi-automatics version of the M16. These feature distinctive upper and lower receivers which can be readily separated via front and rear pins. The upper includes the barrel, handguard, forward gas tube, and bolt assembly, while the lower contains grip, trigger group, fire selector, and mag well. In addition the lower is attached to the stock which encloses the buffer assembly.
The original ArmaLite AR-15 was a select-fire, air-cooled, gas-operated, magazine-fed rifle designed by American gun manufacturer ArmaLite in 1956. It was based on Armalite’s AR-10 rifle chambered for the 7.62×51 NATO (.308 Win). In 1959, ArmaLite sold its rights to the AR-10 and AR-15 to Colt. Some key modifications were made — most notably, the charging handle was re-located from under the carrying handle to the rear of the receiver. The redesigned rifle was adopted by the U.S. military as the M16 carbine, which went into production in March 1964.
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This cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.
While attending the CA Long Range Championship a few seasons back, we had the opportunity to test the performance of a high-magnification (63X) spotting scope in near-ideal conditions (maybe the best I’ve ever witnessed). On the event’s last day we arrived at 5:45 am, literally as the sun was cresting the horizon. I quickly deployed our 
Then I invited 3 or 4 shooters to look through the scope. One younger guy, with good eyes, said immediately: “Yeah, I can see the holes — right there at 4 o’clock and seven o’clock. Wow.” Some older guys, who were wearing glasses, could not see the holes at all, no matter what we did to the scope’s main focus and diopter adjustment.
Chromatic Aberration Revealed
Credit our buddy Joe Friedrich for this simple yet effective accessory for your benchrest rifle. Joe shoots a .22 LR benchrest rig with a barrel tuner. When he added weights to his tuner, he found his rifle no longer balanced well. He wanted to add some weight in the rear without drilling holes in the stock. He also wanted the weight to be removable, and easily placed on another rifle in his stable. He wanted a weight that could be moved from gun to gun as needed.
This approach works reasonably well for the distances encountered in most hunting and target shooting conditions, but breaks down rapidly for long range work. It’s really an archaic approach based on artillery firings conducted in the late 1800s and computational techniques developed before the advent of modern computers.
Some say that a higher fill ratio is good because it prevents the powder from settling differently in the case (which could lead to inconsistent ignition and greater MV SD). This explanation sounds good, and went unchallenged for a long time. However, Applied Ballistics has done some interesting testing that sheds new light on the density issue.
