A Kestrel Wind Meter will record wind speed with its impeller wheel. However, to get the most accurate wind velocity reading, you need to have your Kestrel properly aligned with the wind direction. To find wind direction, first orient the Kestrel so that the impeller runs at minimal speed (or stops), and only then turn the BACK of the Kestrel into the wind direction. Do NOT simply rotate the Kestrel’s back panel looking for the highest wind speed reading — that’s not the correct method for finding wind direction. Rotate the side of the Kestrel into the wind first, aiming for minimal impeller movement. The correct procedure is explained below by the experts at Applied Ballistics.
How to Find the Wind Direction with a Kestrel Wind Meter
Here is the correct way to determine wind direction with a Kestrel wind meter when you have no environmental aids — no other tools than a Kestrel. (NOTE: To determine wind direction, a mounted Wind Vane is the most effective tool, but you can also look at flags, blowing grass, or even the lanyard on your Kestrel).
Step 1: Find the wind’s general direction.
Step 2: Rotate the Wind Meter 90 degrees, so that the wind is impacting the side (and not the back) of the wind meter, while still being able to see the impeller.
Step 3: Fine-tune the direction until the impeller drastically slows, or comes to a complete stop (a complete stop is preferred). If the impeller won’t come to a complete stop, find the direction which has the lowest impact on the impeller.
Step 4: Turn the BACK of the Kestrel towards the direction from which the wind is blowing. Then press the capture button, and record your wind speed.
Do NOT simply point the Kestrel’s back into the wind until you get the highest wind speed — that’s not the correct method.
Share the post "How to Find Wind Direction with a Kestrel Wind Meter"
The Swarovski Optik website features a blog with interesting technical articles. In the “On Target” series of blog stories, Swarovski has provided a handy explanation of how optics systems work, with exploded diagrams of rifle scopes, spotting scopes, and binoculars. CLICK HERE for Swarovski Optics Blog.
Scope Terminology Focusing Lens
The focusing lens is an adjustable lens inside the optical system for focusing the image at different distances…. In the case of rifle scopes, apart from focusing, the focusing lens also facilitates parallax compensation.
For rifle scopes, the reticle can be focused using the diopter adjustment on the eyepiece, thereby correcting any visual impairment. [Editor’s Note: Movable eyepiece diopter adjustment is not offered on all rifle scopes. It is a useful feature on Swarovski and other premium scopes. This allows shooters who need eyeglasses to get a sharply focus image even without wearing corrective lenses. Of course shooters should always wear ANSI-certified eye protection. With the diopter, folks who need correction can use inexpensive, non-Rx safety eyewear instead of expensive prescription safety glasses.]
The purpose of the reversal system is to reverse the image by means of prisms in binoculars and telescopes, and lenses in rifle scopes….The lens reversal system is needed in rifle scopes to control the variable magnification and move the exit pupil[.]
Resource tip by EdLongRange. We welcome reader submissions.
Share the post "Swarovski Tech Blog Reveals How Scopes Work"
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 new 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.)
Barnes has invested heavily in this modern approach. Our 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. Consider the graph below showing a bullet specific drag curve referenced to 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.
Share the post "Barnes Calculates Ballistics Using Doppler Radar Speed Data"
Here’s a smart new product that could save your life (or the life of a loved one). The EPIC-id bracelet stores your vital information on a shockproof, weatherproof USB flash drive that can be instantly accessed by an EMT or doctor. Your Editor just bought two of these med-info bracelets — one for himself and another for a diabetic family member. If you’re a shooter, or spend much time outdoors, you should have this device or some other kind of tag that provides your vital info (such as blood type and drug allergies) to first responders.
If you’re injured, first responders need to know if you have a medical condition, have drug allergies, or take any medications. With this bracelet, that vital info is available even if you can’t communicate. The EPIC-id Emergency Band stores medical data on a USB flash drive that can be “read” by any computer or mobile device with a USB port. Firefighters, EMTs, and medical professionals can instantly determine your name, emergency contacts, insurance, and medical information. (Read my experience below).
It’s easy to load your medical data on to the device. Standardized emergency info forms come pre-loaded — just insert the Epic-ID into any computer to fill out the forms. PC and Mac™ compatible, the waterproof EPIC-id features a durable stainless steel clasp and trim-to-fit silicone band.
Editor’s Story — Why This Is Important
Just this past Wednesday July 8th, at 2:00 am, a family member was rushed to the hospital after suffering a stroke. She was non-responsive and unable to communicate at all. This created problems for EMTs because they were unaware of her current medications, insulin needs, resusitation preferences, and some relevant past medical history. After that experience I decided to buy these bracelets for her and myself. The good new is that she survived… but it was close.
Share the post "Emergency Medical Information Bracelet Holds Digital Data"
So what does a “worn-out” barrel really look like? Tom Myers answered that question when he removed a 6.5-284 barrel and cut it down the middle to reveal throat wear. As you can see, there is a gap of about 5mm before the lands begin and you can see how the lands have thinned at the ends. (Note: even in a new barrel, there would be a section of freebore, so not all the 5mm gap represents wear.) There is actually just about 2mm of lands worn away. Tom notes: “Since I started out, I’ve chased the lands, moving out the seating depth .086″ (2.18 mm). I always seat to touch. My final touch dimension was 2.440″ with a Stoney Point .26 cal collet.”
Except for the 2mm of wear, the rifling otherwise looks decent, suggesting that setting back and rechambering this barrel could extend its useful life. Tom reports: “This was something I just thought I’d share if anyone was interested. I recently had to re-barrel my favorite prone rifle after its scores at 1,000 started to slip. I only ever shot Sierra 142gr MatchKings with VV N165 out of this barrel. It is a Hart and of course is button-rifled. I documented every round through the gun and got 2,300 over four years. Since I have the facilities, I used wire EDM (Electro Discharge Machining) to section the shot-out barrel in half. It was in amazingly good shape upon close inspection.”
Tom could have had this barrel set back, but he observed, “Lately I have had to increase powder charge to maintain 2,950 fps muzzle velocity. So to set it back would have only increased that problem. [And] I had a brand new 30″ Krieger all ready to screw on. I figured it was unlikely I’d get another full season on the old barrel, so I took it off.”
Share the post "A Slice of (Barrel) Life — Inside Look at Barrel Erosion"
While many of us now favor digital photography over “old-fashioned” 35mm film, don’t toss those old 35mm film canisters, especially the clear Fuji-type with secure snap-in lids. Small plastic film canisters have a multitude of uses for the shooter and reloader.
Here Are Things You Can Do with Plastic Film Canisters:
1. If you weigh powder charges after throwing them with a manual powder dispenser, throw the charges first into a film canister and then use that to drop the powder into the measuring pan on your scale. The canister will catch every kernel of powder. If you throw charges directly into a weighing pan, powder can sometimes bounce out. Using the film canister will help keep spilled powder off your loading bench and floor.
2. Store extra sets of foam ear-plugs in the canister. You never want to be without ear protection. This editor has four film canisters filled with plugs. Two go in the range kit, one goes in the car’s glove compartment, and a second stays in a lock box I use to transport pistols. This way I never find myself at the range without ear protection.
At SHOT Show 2013 we had the chance to chat with legendary barrel-maker John Kreiger of Krieger Barrels. In this wide-ranging interview, John addressed a number of questions our readers often pose…. What is better for a 6mm, 0.236″ land or 0.237″ land? What are the pros/cons of various barrel types: 3-groove, 4-groove, 6-groove, 8-groove, and 5R? What types of land/groove configurations clean up more easily? (John says the 5R might be the winner there).
John also discusses barrel cleaning and he explains why it’s unwise to pull a dirty brush back across your delicate crown: “The problem comes from the fact that abrasive materials — powder and primer residues in particular — get embedded in the brush. Essentially that is how a lap works.”
When we suggested that Krieger Barrels might want to offer three-groove barrels in the future, John surprised us by revealing that he has been considering putting a 3-groove design into production. John says that, in theory at least, a canted-land 3-groove holds a lot of promise. John hopes to build some prototype 3-grooves to test. Krieger Barrels has a 300-yard underground tunnel where barrels with various land/groove configurations and calibers can be tested using a return-to-battery fixture. John admits that tunnel testing of barrels is “on the back burner” as his company focuses on filling orders. But he says that he has a strong personal interest in testing different land/groove configurations, different amounts of choke, and different internal dimensions. We hope we’ll be able to share some results from the Krieger Barrels test tunnel in the near future.
Share the post "John Krieger Talks about Barrel-Making"
Forum member Rich DeSimone uses a handy “Stub Gauge” for setting shoulder “bump” and seating depth. The gauge is made from a section of barrel lopped off when the muzzle is crowned. The chambering reamer is run in about 1/4 of the way, enough to capture the neck and shoulder area of the case. Rich then uses his full-length die to “bump” a master case with the ideal amount of headspace for easy feeding and extraction. He takes that case and sets it in this Stub Gauge, and measures from the front of the gauge to the rim. He can then quickly compare any fired case to a his “master” case with optimal headspace. Since the gauge measures off the shoulder datum, this tells him how much to bump his fired brass.
In addition, the Stub Gauge can be used to set bullet seating-depth. Rich has a channel cut transversely on one side of the gauge, exposing the throat area. Since the interior of the gauge is identical to the chamber in his gun, this lets him see where a seated bullet engages the rifling. He can tinker with bullet seating length until he gets just the right amount of land contact on the bullet, confirmed visually. Then he measures the case OAL and sets his seating dies accordingly. This is much handier than using a Stoney Point Tool to measure distance to the lands. As your barrel’s throat wears, you may seat your bullets out further to “chase the lands”, but the gauge provides a constant land engagement point, in the barrel’s “as new” condition. By measuring the difference between the land contact point on the gauge and the actual contact point on your barrel, you can determine throat “migration”.
Share the post "Use Stub Gauge to Check Shoulder ‘Bump’ and Seating Depth"
It’s vitally important to keep your ammo at “normal” temps during the hot summer months. Even if you use “temp-insensitive” powders, studies suggest that pressures can still rise dramatically when the entire cartridge gets hot, possibly because of primer heating. It’s smart to keep your loaded ammo in an insulated storage unit, possibly with a Blue Ice Cool Pak if you expect it to get quite hot. Don’t leave your ammo in the car or truck — temps can exceed 140° in a vehicle parked in the sun.
To learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.
For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”
Share the post "Tech Tip: Keep Your Ammo Cool this Summer"
OK, admit it — you’ve always wondered how they get those color swirls and camo patterns in McMillan stocks. (You’ll be surprised at the answer). And how does McMillan manage to inlet stocks so precisely for so many different action types?
McMillan Stocks is one of the leading fiberglass stock producers, cranking out 8,000-10,000 stocks every year for hunters, target shooters, and members of the military. McMillan employs state-of-the-art, high-tech machinery. At the same time, many processes are still done by hand — such as applying colors to the stocks.
In the videos below, Kelly McMillan hosts Bob Beck of Extreme Outer Limits TV in a tour of the McMillan stock-making facility. We think all avid “gun guys” will be fascinated by these high-quality videos.
McMillan Custom Stock Production
The first video shows the stock-building operation from start to finish — You’ll see the lay-up, color application, molding, and “stuffing”. Watch carefully at 0:16 to see colors being applied.
Readers who have just recently discovered the Daily Bulletin may not realize that AccurateShooter.com has hundreds of reference articles in our archives. These authoritative articles are divided into mutiple categories, so you can easily view stories by topic (such as competition, tactical, rimfire, optics, shooting skills etc.). One of the most popular categories is our Technical Articles Collection. On a handy index page (with thumbnails for every story), you’ll find over 100 articles covering technical and gunsmithing topics. These articles can help you with major projects (such as stock painting), and they can also help you build more accurate ammo. Here are five popular selections from our Technical Articles archive.
Complete Precision Case Prep. Jake Gottfredson covers the complete case prep process, including brass weight sorting, case trimming, primer pocket uniforming, neck-sizing, and, case-neck turning.
At long range, small bullet holes are much easier to see “in the white” than in the black center of the normal High Power target. When you’re practicing at long range using a scoped rifle, one way to enhance your ability to see your bullet holes is to print a “negative” version of the regulation bullseye target so that your black center is now white.
How do you create a “negative” of a target image? Many image programs, including the FREE Irfanview software, have a “Negative” function in the pull-down menu. If you don’t see a “Negative” menu option in your program, look for a “substitute colors” option. Many printers also have a “reverse colors” function. If you can’t find a solution with your computer or printer, just take a normal bullseye target to a copy shop, and the staff can easily print you a set of targets with white centers in black fields.
The .260 Remington and the 6.5×55 Swedish (aka 6,5x55mm SE) are both very popular cartridges with hunters and target shooters. The 6.5×55 has a long military heritage and a great record as a hunting round. The .260 Rem, essentially a .308 Win necked down to .264 caliber, is a more recent cartridge, but it grows in popularity every year, being one of the top cartridges for tactical/practical competitions. It offers better ballistics and less recoil than the parent .308 Win cartridge. In our Shooter’s Forum, respected UK gun writer Laurie Holland provided a good summary of the differences between the two chamberings. Laurie writes:
The 6.5×55 case has 6 or 7% more capacity than the .260s, even more in practice when both are loaded to standard COALs with heavy bullets, which sees them having to seated very deep in the .260 Rem using up quite a lot of powder capacity. So loaded up for reasonable pressures in modern actions, the 6.5×55 will give a bit more performance.
The issue for many is what action length is available or wanted, the 6.5×55 requiring a long action. So sniper rifle / tactical rifle competitors will go for the .260 Rem with the option of the many good short-bolt-throw designs around with detachable box magazines (DBMs). If a bit more performance is needed, the .260 AI (photo right) can yield another 100-150 fps velocity, depending on bullet weight.
Berger Twist-Rate Stability Calculator
On the updated Berger Bullets website you’ll find a handy Twist-Rate Stability Calculator that predicts your gyroscopic stability factor (SG) based on mulitiple variables: velocity, bullet length, bullet weight, barrel twist rate, ambient temperature, and altitude. This very cool tool tells you if your chosen bullet will really stabilize in your barrel.
LIVE DEMO BELOW — Just enter values in the data boxes and click “Calculate SG”.
Those of us over-50 types can use some help when shooting iron sights. As one gets older, your eyes lose the ability to rapidly adjust to different points of focus. In practice, when shooting a rifle, this means the target image may be sharp but the sights are blurry, or vice-versa. Or you may be able to see the target and front sight reasonably well, but the rear sight is a complete blur. (That is this Editor’s problem when shooting a rifle, such as a Swedish Mauser, with a notched blade rear sight.) Even if you are using a rear peep sight, you may see a blurry rear circle (or two circles if you have astigmatism). Placing a diopter sight (sighting disc) on your shooting glasses can help many people see open sights better, when shooting both handguns and rifles.
Merit Corp. in Schenectady, NY, offers an adjustable optical disc that attaches to shooting glasses with a rubber cup. Though primarily intended for pistol shooters, the Merit optical attachment can also be helpful when shooting rifles with open sights, such as military bolt actions. Priced at $65.00, the Merit device features a shutter-style, adjustable aperture iris.
You never want your barrel to get too hot. Accuracy suffers when barrels over-heat, and excessive heat is not good for barrel life. So how do you monitor your barrel’s temperature? You can check if the barrel is “warm to the touch” — but that method is not particularly precise. There is a better way — using temperature-sensitive strips. McMaster.com (a large industrial supply house) offers stick-on temp strips with values from 86° F to 140° F. A pack of ten (10) of these strips (item 59535K13) costs $10.71. So figure it’ll cost you about a buck per barrel for strips. That’s cheap insurance for your precious barrels.
Western Powders (vendors of Accurate, Norma, and Ramshot powders), publishes a Blog that covers all aspects of hand-loading and rifle maintenance. Recently the Western Powders Blog published a Q & A series entitled Dear Labby: Questions for our Ballistics Lab. Here are some excerpts that pertain to powder storage and shelf life. Worried that your powder may be too old? Western’s experts explain how to check your propellants for warning signs.
Proper Powder Storage
Q: I live in southern Arizona where it is very hot. I am told powders will become unstable if stored in an area not air-conditioned. My wife says no powder or primers in the house. Can powder be stored in a refrigerator? What about using a fireproof safe? I would appreciate your ideas. — M.C.
Lab Answer: SAAMI guidelines are pretty clear on issues of storage. They recommend storing smokeless powder in containers that will not allow pressure to build if the powder is ignited — ruling out gun safes and refrigerators.
On some internet shooting forums, self-declared “experts” advise new rifle shooters to stick to low-end factory rifles. These “experts” (many of whom don’t own a single really accurate rifle), claim that it will take years for a new shooter to learn how to shoot a rifle accurately. So, the argument goes, the accuracy offered by a precision-chambered rifle, with a custom barrel, is “wasted” on a new shooter.
We disagree with that viewpoint, at least when it comes to rifles shot from a rest. Certainly it takes time for a complete novice to learn how to handle the gun and to work the trigger smoothly. However, we’ve seen relatively new shooters, with help from a skilled mentor, do remarkably well with precision rifles right from the start. With a good bench gun, many new shooters can shoot well under 1 MOA on the first day. This editor has personally seen some inexperienced ladies try their hand at benchrest shooting, and within a month or two they are shooting on a par with the “good old boys” in serious competition.
You have to admire someone with serious do-it-yourself skills. Not just hammer and nail skills, but formidable design and fabrication skills. Well Forum Member Dave D. (aka “AKShooter”) has a DIY skill set that might put some trained machinists to shame. You see, “DIY Dave” crafted his own pedestal front rest from scratch, using his own design and about $100.00 in materials (not counting the Edgewood front bag). Dave estimates he put 20 hours of labor into the project, but the end result was worth it: “This Do-It-Yourself rest drives like a dream. I’ve played with the Caldwell and a Sinclair, they have nothing on this one.”
Dave tells us: “Here is my Do-It-Yourself front rest. I wanted to show other folks who are handy that a solid front rest is doable with a bit of time — and you don’t need to spend $1000.00. (You could say this is a design for shooters with more time than money.) This is for F-Class. I was originally overwhelmed by the equipment needed, so I decided to make my own rest. I didn’t have the money for a SEB or Farley Coaxial. This is what I’ll run this season (my second as an F-Class competitor).”
Here’s a great Do-It-Yourself (DIY) project from Martin Tardif. Build your own height-adjustable ammo caddy for under ten bucks. This is a great project for F-Open competitors as well as anyone who shoots with a pedestal front rest, either on the ground or from a bench. The ammo caddy attaches, via a flexible arm, to your front rest. The flexy arm allows you to position your ammunition close to your rifle’s feeding port. That makes it easy to grab cartridges and load them into the chamber without shifting your shooting position. Nice job Martin!