These four photos show the substantial changes in the shock wave and turbulence patterns for the same 7.5mm bullet at different velocities. The “M” stands for Mach and the numerical value represents the velocity of the bullet relative to the speed of sound at the time of the shot. Photos by Beat Kneubuehl.
“Going transonic” is generally not a good thing for bullets. The bullet can lose stability as it enters the transonic zone. It can also become less slippery, losing BC as a consequence of dynamic instability. In this video, Bryan Litz of Applied Ballistics analyzes what happens to bullet stability (and BC) as projectiles approach the speed of sound. Transonic effects come into play starting about Mach 1.2, as the bullet drops below 1340 fps.
Transonic Ballistics Effects Explainedby Bryan Litz
What happens when the bullet slows to transonic speed, i.e. when the bullet slows to about 1340 feet per second? It is getting close to the speed of sound, close to the sound barrier. That is a bad place to fly for anything. In particular, for bullets that are spin-stabilized, what the sound barrier does to a bullet (as it flies near Mach 1) is that it has a de-stabilizing effect. The center of pressure moves forward, and the over-turning moment on the bullet gets greater. You must then ask: “Is your bullet going to have enough gyroscopic stability to overcome the increasing dynamic instability that’s experienced at transonic speed?”
Some bullets do this better than others. Typically bullets that are shorter and have shallow boat-tail angles will track better through the transonic range. On the contrary, bullets that are longer… can experience a greater range of pitching and yawing in the transonic range that will depress their ballistic coefficients at that speed to greater or lesser extents depending on the exact conditions of the day. That makes it very hard to predict your trajectory for bullets like that through that speed range.
When you look at transonic effects on stability, you’re looking at reasons to maybe have a super-fast twist rate to stabilize your bullets, because you’re actually getting better performance — you’re getting less drag and more BC from your bullets if they are spinning with a more rigid axis through the transonic flight range because they’ll be experiencing less pitching and yawing in their flight.
To determine how bullets perform in the “transonic zone”, Bryan did a lot of testing with multiple barrels and various twist rates, comparing how bullets act at supersonic AND transonic velocities. Bryan looked at the effect of twist rates on the bullets’ Ballistic Coefficient (BC). His tests revealed how BC degrades in the transonic zone due to pitching and yawing. Bryan also studied how precision (group size) and muzzle velocity were affected by twist rates. You may be surprised by the results (which showed that precision did not suffer much with faster barrel twist rates). The results of this extensive research are found in Bryan’s book Modern Advancements in Long Range Shooting.
Bryan notes: “A lot of gunpowder was burned to get these results and it’s all published in layman’s terms that are easy to understand”. If you’re interested in learning more about transonic bullet stability, you may want to pick up a copy of Bryan’s book.
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Tech Tip by Doc Beech, Applied Ballistics Support Team
I am going to hit on some key points when it comes to bullet pointing. How much pointing and trimming needed is going to depend on the bullet itself. Specifically how bad the bullets are to begin with. Starting out with better-quality projectiles such as Bergers is going to mean two things. First that you don’t need to do as much correction to the meplat, but also that the improvement is going to be less. NOTE: We recommend you DO NOT POINT hunting bullets. Pointing can affect terminal performance in a bad way.
NOTE the change in the bullet tip shape and hollowpoint size after pointing:
Don’t Over-Point Your Bullets
What is important here is that you never want to over-point. It is far better to be safe, and under-point, rather than over-point and crush the tips even the slightest bit. To quote Bryan Litz exactly: “Best practice is to leave a tiny air gap in the tip so you’re sure not to compress the metal together which will result in crushing. Most of the gain in pointing is taking the bullet tip down to this point. Going a little further doesn’t show on target”. So in essence you are only bringing the tip down a small amount… and you want to make sure you leave an air gap at the tip.
Also keep in mind, bullet pointing is one of those procedures with variable returns. If you only shoot at 100-200 yards, bullet pointing will likely not benefit you. To see the benefits, which can run from 2 to 10% (possibly more with poorly designed bullets), you need be shooting at long range. Bryan says: “Typically, with pointing, you’ll see 3-4% increase in BC on average. If the nose is long and pointy (VLD shape) with a large meplat, that’s where pointing has the biggest effect; up to 8% or 10%. If the meplat is tight on a short tangent nose, the increase can be as small as 1 or 2%.” For example, If you point a Berger .308-caliber 185gr Juggernaut expect to only get a 2% increase in BC.
Should You Trim after Pointing?
Sometimes you can see tiny imperfections after pointing, but to say you “need” to trim after pointing is to say that the small imperfections make a difference. Bryan Litz advises: “If your goal is to make bullets that fly uniformly at the highest levels, it may not be necessary to trim them.” In fact Bryan states: “I’ve never trimmed a bullet tip, before or after pointing”. So in the end it is up to you to decide.
Pointing is Easy with the Right Tools
The process of pointing in itself is very simple. It takes about as much effort to point bullets as it does to seat bullets. We are simply making the air gap on the tip of the bullet ever-so smaller. Don’t rush the job — go slow. Use smooth and steady pressure on the press when pointing bullets. You don’t want to trap air in the die and damage the bullet tip. You can use most any press, with a caliber-specific sleeve and correct die insert. The Whidden pointing die has a micrometer top so making adjustments is very easy.
Bryan Litz actually helped design the Whidden Bullet Pointing Die System, so you can order the Pointing Die and Inserts directly from Applied Ballistics. Just make sure that you pick up the correct caliber sleeve(s) and appropriate insert(s). As sold by Applied Ballistics, the Whidden Bullet Pointing Die System comes with the die, one tipping insert, and one caliber-specific sleeve. To see which insert(s) you need for your bullet type(s), click this link:
In this video, Bryan Litz of Applied Ballistics explains how to choose a bullet for long-range shooting and explains what you should be looking for when developing a long-range load. Bryan notes that, with a new rifle build, the bullet you select may actually dictate your gun components. When starting from a “clean slate”, once you select a bullet, you will then pick a barrel, twist rate, and cartridge that are appropriate for that bullet. In choosing a long-range projectile, Bryan recommends you choose a high-BC bullet “that is known for precision”. Then you need to find an ultra-consistent, reliable load.
This video is worth watching. Bryan Litz makes some very good points.
Load Development — Why Consistency is Key (and Half-MOA May Be Good Enough)
After choosing a bullet for your long-range project, then you need to develop a load through testing. Bryan explains: “Once you’ve selected a bullet … and you have selected the components around that bullet, the most important thing to remember in hand-loading is consistency. You’re going to do some testing to see what combination of powder charge, powder type, and seating depth give you the best groups and lowest standard deviations in muzzle velocity.”
Bryan says that if you develop a load that can shoot consistent, half-minute groups in all conditions, you should be satisfied. Bryan says that many long-range shooters “spin their wheels” trying to achieve a quarter-MOA load. Often they give up and start all over with a new bullet, new powder, and even a new cartridge type. That wastes time, money, and energy.
Bryan cautions: “My advice for hand-loaders who are long-range shooters, is this: If you can get a load that is reliable and can shoot consistent, half-minute groups with low MV variation and you can shoot that load in any condition and it will work well, then STICK with THAT LOAD. Then focus on practicing, focus on the fundamentals of marksmanship. The consistency you develop over time by using the same ammunition will mean more to your success in long range shooting than refining a half-minute load down to a quarter-minute load.”
Bryan notes that, at very long range, shooting skills and wind-calling abilities count most: “Your ability to hit a 10″ target at 1000 yards doesn’t improve very much if you can make your rifle group a quarter-minute vs. a half a minute. What’s going to determine your hit percentage on a target like that is how well you can calculate an accurate firing solution and center your group on that target. A lot of people would be more effective if they focused on the fire solution and accurately centering the group on the target [rather than attempting to achieve smaller groups through continuous load development].”
Editor’s Note: We agree 100% with the points Bryan makes in this video. However, for certain disciplines, such as 600-yard benchrest, you WILL need a sub-half-MOA rifle to be competitive at major matches. Well-tuned, modern 600-yard benchrest rigs can shoot 1/4-MOA or better at 100 yards. Thankfully, with the powder, bullets, and barrels available now, 1/4-MOA precision (in good, stable conditions) is achievable with a 17-lb benchgun built by a good smith with premium components.
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The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.
Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”
The simple answer to that is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.
G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferrable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.
Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, believes the G7 standard is preferrable for long-range, low-drag bullets: “Part of the reason there is so much ‘slop’ in advertised BCs is because they’re referenced to the G1 standard which is very speed sensitive. The G7 standard is more appropriate for long range bullets. Here’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:
G1 BCs, averaged between 1500 fps and 3000 fps:
Berger 180 VLD: 0.659 lb/in²
JLK 180: 0.645 lb/in²
The reason the BC for the JLK is less is mostly because the meplat was significantly larger on the particular lot that I tested (0.075″ vs 0.059″; see attached drawings).
For bullets like these, it’s much better to use the G7 standard. The following BCs are referenced to the G7 standard, and are constant for all speeds.
Many modern ballistics programs, including the free online JBM Ballistics Program, are able to use BCs referenced to G7 standards. When available, these BCs are more appropriate for long range bullets, according to Bryan.
[Editor’s NOTE: BCs are normally reported simply as an 0.XXX number. The lb/in² tag applies to all BCs, but is commonly left off for simplicity.]
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The digital archives of Shooting Sports USA magazine (SSUSA) features an Expert Forum on Wind Reading. This outstanding article on wind reading starts off with a section by ballistics guru Bryan Litz, author of Applied Ballistics for Long-Range Shooting. Then five of the greatest American shooters in history share their personal wind wisdom. Lanny Basham (Olympic Gold Medalist, author, Winning in the Wind), Nancy Tompkins (Past National HP Champion, author, Prone and Long-Range Rifle Shooting), David Tubb (11-Time Camp Perry National Champion), and Lones Wigger (Olympic Hall of Fame) all offer practical wind-reading lessons learned during their shooting careers.
Shooting Sports USA magazine (SSUSA) recently rolled out a modern, mobile-friendly website. Log on to www.ssusa.org. There you’ll find current news stories as well as popular articles from the SSUSA archives. The new SSUSA website also includes match reports, plus expert tips from the USAMU. In fact, today’s feature story on the SSUSA.org site comes from the USAMU. The article compares single-stage presses with progressive presses. If you are considering buying a new press, check out this article: Should I Buy a Single-Stage Press, or a Progressive?
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One recent trend in F-TR competition is the use of low-profile, benchrest-type stocks shot with a light hand-hold and little or no face contact. For this method of F-TR shooting to work, you need the right equipment, and practice a “minimalist” shooting technique. One of the pioneers in this style of F-TR shooting is action-maker John Pierce of Pierce Engineering. Above you can see John shooting one of his F-TR rifles at the 2015 Canadian F-Class Championships. Note the straight-line stock and see how the adjustable bipod is set quite low to the ground (in fact the bipod’s arms are almost straight out).
Members of the Michigan F-TR Team, including Bryan Litz, have used similar rigs with success. Bryan said it took a while to adapt his shooting technique to this kind of rig, but there is a pay-off. Armed with a Pierce-built F-TR rifle, Bryan won his first-ever F-TR Match. Bryan explains the technique he uses when shooting this kind of rifle:
“Coming over from sling shooting, I knew there would be unique challenges to F-TR which I wanted to learn prior to (not during) a major tournament. I learned a new shooting position which doesn’t involve drawing the right knee up. For F-TR I get more straight behind the gun rather than at an angle. I found that the rifle shoots best with very light cheek, shoulder and grip pressure, approaching free recoil. This is how Eric Stecker shot his similar rifle into second place in the SW Nationals [with high X-Count by a large margin]. I learned the rifle’s sensitivity to different bipod and rear bag supports, and found the best buttplate position to allow the rifle to track and stay on target after recoil. This set-up shot best with a mostly free-recoil approach, that means ‘hovering’ over the comb, rather than resting your head on the stock. This took some ‘getting used to’ in terms of neck and back muscle tone. These are the kind of details I think it’s important to focus on when entering a new discipline.”
Bryan’s Pierce-built F-TR rig is a tack-driver: “I can certainly vouch for this set-up! In last weekend’s mid-range State Championship in Midland, MI, I shot my Pierce rifle into first place with a 598-44X (20 shots at 300, 500 and 600). Once you get used to the positioning and way of shooting these rifles, they just pour shots through the center of the target.”
Pierce F-TR Rifles with Scoville Stocks
Shown below are three complete Pierce F-TR rifles, along with a barreled action for comparison. The carbon-fiber/composite stocks are built by Bob Scoville. These Scoville stocks are very light, yet very strong and very stiff.
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Bryan Litz has produced an informative new video on the subject of bullet stability. The video explains how stability is related to spin rate (or RPM), and how RPM, in turn, is determined by barrel twist rate and velocity. For long-range shooting, it is important that a barrel have a fast-enough twist rate to stabilize the bullet over its entire trajectory.
Detailed Bullet Stability Article
To complement the above video, Bryan has authored a detailed article that explains the key concepts involved in bullet stabilization. Bryan explains: “Bullet stability can be quantified by the gyroscopic stability factor, SG. A bullet that is fired with inadequate spin will have an SG less than 1.0 and will tumble right out of the barrel. If you spin the bullet fast enough to achieve an SG of 1.5 or higher, it will fly point forward with accuracy and minimal drag.”
There is a “gray zone” of marginal stability. Bryan notes: “Bullets flying with SGs between 1.0 and 1.5 are marginally stabilized and will fly with some amount of pitching and yawing. This induces extra drag, and reduces the bullets’ effective BC. Bullets in this marginal stability condition can fly with good accuracy and precision, even though the BC is reduced. For short range applications, marginal stability isn’t really an issue. However, shooters who are interested in maximizing performance at long range will need to select a twist rate that will fully stabilize the bullet, and produce an SG of 1.5 or higher.”
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”.
In this detailed 22-minute video, John McQuay of 8541 Tactical shows how to input firearm specs, MV, and BC into a Kestrel 4500 NV (Applied Ballistics model). This handy unit combines a Kestrel Weather meter with a full-fledged ballistics computer.
Step-by-step the video shows how to set up all the important variables. The video shows how to input Muzzle Velocity, Bullet BC (G1 or G7), Zero Distance and the other key ballistics variables. In addition, the video explains how to input gun-specific data such as bore height, barrel twist rate, and barrel rifle twist direction (right-hand vs. left-hand). (Twist direction comes into play in long range spin drift calculations).
If you own a Kestrel 4500 NV (Applied Ballistics), we think you’ll find this video helpful — particularly when it comes to setting up some of the lesser-known data items. The video also offers tips on navigating through the menus most efficiently.
You’ve heard the rumors of a new ultra-high BC 7mm bullet from Berger. Well the rumors are true. Berger is now shipping test samples of its new 195-grain 7mm Elite Hunter Bullet, part # 28550. This bullet boasts jaw-droping 0.755 G1 and 0.387 G7 Ballistic Coefficients. Those are stunningly high numbers. Compare that to 0.674 G1 and 0.345 G7 BCs for the previous BC king amoung 7mm projectiles, Berger’s own 180 gr Match Hybrid Target.
We’re certain the “orange box” 195gr Elite Hunter will soon see use by F-Open competitors. This ultra-high BC projectile could be a “game-changer” in long-range shooting when used in cartridges such as the 7mm RSAUM, 7mm WSM and even bigger 7mm magnums. Recommended barrel twist rate is 1:8.3″, with a stated “minimum” twist of 1:9″.
We ran some numbers through the JBM Ballistics program*, comparing the new 195-grainer with Berger’s popular 180gr Hybrid. The results were eye-opening. The projected drop is significantly less. Most importantly, this new 195gr bullet moves a LOT less in the wind at 1000 yards. This should translate into higher scores for F-Class shooters — that wide ‘9’ shot may stay in the ’10’ ring. In fact, based on the JBM trajectory calculation, with a 10 mph 90° crosswind, the 195gr bullet will have over SEVEN INCHES less wind drift at 1000 yards than the 180-grainer (46.0″ vs. 53.1″). That’s a big deal, a very big deal…
Drop at 800 yards: 135.5″
Windage at 800 yards: 28.0″
Drop at 800 yards: 140.9″
Windage at 800 yards: 32.2″
Drop at 1000 yards: 237.9″ Windage at 1000 yards: 46.0″
Drop at 1000 yards: 250.0″ Windage at 1000 yards: 53.1″
Drop at 1200 yards: 380.1″
Windage at 1200 yards: 69.6″
Drop at 1200 yards: 404.2″
Windage at 1200 yards: 81.2″
* Variables were set to 55.4° F, 1000′ elevation, standard Atmosphere at Altitude, 2950 fps muzzle velocity. You can use JBM Ballistics to compare at different MVs.
UPDATE from Berger
After we broke this story, Berger Bullets wanted to clarify some points. Berger explained:
“This bullet is in the testing phase and has not been officially launched. We sent this bullet out for some public testing to make sure that we had positive feedback before we moved forward with an official launch.
We want to see how it performs in multiple rifles and different chamberings.
This bullet was made for hunting purposes, we realize there are shooters who would like to take these out for target shooting, like F-Class. However, we are not certain how they will perform. If things are successful we would like to eventually launch a target version.”
The information on the label you have pictured on your article has been updated.
G7 BC: .387
G1 BC: .754
How to Get Berger’s 195gr Elite Hunter Bullets
These bullets are so new you won’t find them on the Berger Bullets website yet. As Berger explained above, these bullets are still in a final testing phase. Most of the early production runs have been sent out for testing purposes. If you have specific questions, you can send an email to Berger via this CONTACT PAGE. Otherwise you can phone Berger, Mon-Fri, at 714-441-7200. Please try the email option first.
Applied Ballistics has created a new series of YouTube videos about precision long range shooting. Featuring ace long-range shooter and professional ballistician Bryan Litz, these videos address various topics of interest to long-range marksmen. In this week’s video, the second in the series, Bryan Litz examines the most common causes of ballistics shooting errors at Long Range.
Watch Applied Ballistics Video about Common Mistakes in Long Range Shooting:
Bryan Litz of Applied Ballistics often hears the question: “What are the main reasons people miss their target at long range?” To answer that question, in this video, Bryan explains the most important variables in Long Range shooting. Bryan says: “Probably the number one thing is range — you have to have a [precise] range to your target because your bullet is dropping, and to hit the target you need to correct for bullet drop.” Distance may be indicated on the target bay (or berm), but for open ranges you should ascertain distance-to-target with a quality laser rangefinder. Even when the distance to target is shown with a sign or marker, you may want to confirm the distance with your rangefinder. (You may be surprised — we’ve seen marked target distances at commercial ranges off by 25+ yards!) Bryan says: “Get a good laser range to the target and you’ll be within a couple yards”.
After distance to target, the most important variable is the wind. This is the most challenging factor because the wind is constantly changing. Bryan explains: “After 300 or 400 yards, the wind [will] move your shots off the target if you don’t correct for it. The best way to account for the wind is to measure it at your location with a Kestrel. The Kestrel can give you the speed and direction of the wind at your location, which can baseline your wind call for your long-range shot.” Bryan acknowledges that there will still be variables: “The wind isn’t always blowing the same downrange as at your location… and the wind is always changing”. Bryan notes that you need to account for variances in wind between the time you gauge the wind angle and velocity and the time you actually you take your shot.
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Applied Ballistics has created a new series of YouTube videos about precision long range shooting. Featuring ace long-range shooter and professional ballistician Bryan Litz, these videos will address various topics of interest to long-range marksmen. In this week’s video, the first in the series, Bryan Litz answers the question, “Just What Is Long Range Shooting?” Bryan discusses how we define “long range” and the key factors shooters need to consider.
Applied Ballistics Video — What Is Long Range Shooting?
Bryan states: “I don’t think there is a clear definition of where Long Range starts.” But he offers this practical guideline: “The way I think of it, any time you’re making major adjustments to your zero in order to hit a target, due to gravity drop and wind deflection, THEN you’re getting into ‘Long Range’. For example, if you are zeroed at 100 yards and need to shoot to 600 yards, you have many feet of elevation [drop] to account for, and to me, that’s where it becomes Long Range.”
Extended Long Range and the Transonic Zone
Bryan adds a second concept, namely “Extended Long Range”. Litz says that: “Extended Long Range starts whenever the bullet slows to its transonic range. As the bullet slows down to approach Mach 1, it starts to encounter transonic effects, which are more complex and difficult to account for, compared to the supersonic range where the bullet is relatively well-behaved.” Bryan notes that bullets start to encounter transonic effects at about 1340 fps, quite a bit faster than the speed of sound, which is about 1116 fps at sea level in normal conditions (59° F).
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Photo shows Bryan Litz (on right) and tester Mitchell Fitzpatrick. Bryan said: “Only 2,445 rounds to go! We’re testing over 50 ammo types in five different twist barrels… science can be exhausting!”
Do you know the actual BC (Ballistic Coefficient) of your rimfire ammunition? Well Applied Ballisitics will soon have answers for you. Bryan Litz and his team of testers have been working on a Herculean project. They’ve been testing over fifty types of .22 LR ammo, using five different twist-rate barrels.
Applied Ballistics has just released a fully upgraded version of its popular Tactical App for Android devices. Bryan Litz tells us: “AB Tactical has received a major overhaul (including a new Bullet Library with over 420 options). The upgrade will require that you uninstall the previous version that you have of the application and then install this new version. This is due to the complete re-write of the internal database handling.” NOTE: You need to record your gun-specific data before you install the new version. Details of the updated AB Tactical App are featured in the new 19-page USER Manual.
NOTE: This upgrade is for the Applied Ballistics Tactical Version only. There is no iPhone version of this App, and this is not the standard app that can be purchased from Google Play, or iTunes.
The new version of AB Tactical has a host of important enhancements:
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”.
Berger Bullets has just announced a new 6.5 mm (.264 caliber) 130gr Hybrid projectile. Optimized for magazine-length seating (and AR10-friendly), the new 130gr bullets should be ideal for tactical comps and the PRS series. We expect this new bullet to work great when loaded in modern mid-size cartridges such as the 6.5×47 Lapua and 6.5 Creedmoor. Berger’s new 6.5mm 130gr Match AR Hybrid OTM Tactical bullet (could Berger come up with a longer name?) will soon be released to the public. Berger says this new 130-grainer is the first of many new bullet designs to be introduced in the next few years. Here is a run-down on the new bullet from its designer, Bryan Litz of Applied Ballistics.
NEW 130gr Hybrid — Behind the Design
by Bryan Litz, Berger Chief Ballistician
Intelligent bullet design and selection begins with an understanding of application constraints. For bullets that will be used in unlimited rifles, there are few constraints and performance can truly be maximized. However, many shooting applications have realistic constraints such as magazine feeding of loaded rounds. In constrained applications, you need to ask the question: “What’s the best bullet that will work within the constraints of my shooting application?”
The new Berger 6.5mm 130 grain AR Hybrid OTM Tactical bullet is specifically optimized for maximum performance in magazine-length ammo.
6.5mm cartridges are the second most common cartridges used by top shooters in many of the Precision Rifle Series (PRS) matches, with 6mm being the most common. These kinds of tactical matches all have stages that require repeating rifles — either AR-10 platforms or bolt guns — so magazine feeding is a must. Recognizing that Berger did not have an option that was truly optimized for this particular application, we went to work and the latest 6.5mm Hybrid is the result.
The new Berger 6.5mm 130 grain AR Hybrid OTM Tactical bullet is specifically optimized for use in loaded ammo with COAL constraints for magazine feeding. This bullet maximizes overall performance through BC as well as achievable muzzle velocity in mid-capacity 6.5mm cartridges fed from AR-length magazines.
What makes this bullet optimal for magazine length ammo? To start with, the nose of the bullet is constrained in length so that when it’s loaded to mag length in 6.5mm cartridges such as the 6.5mm Creedmoor, 260 Remington and 6.5×47 Lapua, the nose of the bullet won’t be pushed below the case mouth. This can be an issue with some of the heavier 6.5mm bullets like the 140s. Furthermore, the hybrid ogive design is not sensitive to jump distance like some other designs such as the VLD.
Another consideration of length-constrained ammo is how much of the bullet is pushed down into the case. The inside of the case is for powder, and the more space you take up with bullet, the less powder you can fit in. Less powder means less total energy available, and muzzle velocity is depressed. A bullet weight of 130 grains is an optimal balance between external ballistic performance (BC) and internal case capacity considerations which translate into muzzle velocity. Further to this objective, the AR Hybrid has a minimal air gap in the front of the nose, which allows the bullet to have an even shorter OAL. When dealing with length-constrained designs, you need to pack as much bullet into as little length as possible< to optimize overall performance. Another advantage of making the bullet shorter is that stability, including transonic stability, is improved.
Although this design is length-constrained, the combination of a hybrid ogive and 7 degree Boat Tail produce a very respectable G7 form factor of 0.920 which is within 1% of the popular 6mm 105 grain Hybrid. See below for full live fire ballistic performance data.
The 6.5mm 130 grain AR Hybrid will be barely stable from a 1:9″ twist, and reaches full stability from a 1:8″ twist which is common for many 6.5mm rifles. Visit the Berger Bullets twist rate calculator to get more detailed stability information on your specific barrel twist, muzzle velocity and environment.
Cartridge Selection for Magazine Length Constraint — Advanced Analysis
The trend to smaller calibers in magazine-fed rifles is happening for a very good reason. For a .308 Winchester round, you only have 2.37 calibers of nose length available for the bullet to protrude from the case. Such a short nose will have relatively high drag for the caliber. By contrast, smaller calibers such as 6.5mm and 6mm have proportionally more length available for the nose to protrude from the case and still fit in the same COAL constraint. Proportionally longer noses mean lower drag. Proportionally longer bullets mean higher sectional density. Combine an elevated sectional density with lower drag, and you get higher BC bullets. For example, consider a 175 grain .30 caliber bullet commonly used in .308 Winchester M118LR-type ammo. These 175 grain bullets have G7 BCs in the neighborhood of .243 to .260. Neck the .308 down to 6.5mm (260 Remington) or 6mm (.243 Winchester) and now look at the BCs of the bullets available in these calibers which work within the same magazine length constraint. The 6.5mm 130 grain AR Hybrid has a G7 BC of 0.290, and the 6mm 105 grain Hybrid has a G7 BC of 0.278 — both of which are higher than the .30 cal 175 grain bullet BC. Furthermore, you get hundreds of feet per second more velocity with the necked-down cartridges as well.
All of the above translates into higher hit percentage. See the caliber comparison chart below* which is an excerpt taken from the book: Modern Advancements in Long Range Shooting which addresses this and many other topics in even more detail.
*The Weapon Employment Zone (WEZ) analysis shown above is for a 1000-yard shot on a standard IPSC silhouette in an uncertain environment having: +/- 2 mph wind, +/- 1 yard range, Muzzle Velocity SD of 10 fps, and a rifle shooting 1 MOA groups.
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Following Sierra’s introduction of Tipped MatchKing (TMK) bullets, Bryan Litz of Applied Ballistics LLC has received many requests to determine the Ballistic Coefficient (BC) of these bullets through testing. Below are Litz’s findings for four out of the six bullets he has able to acquire and test so far.
As you can see from the above table, when Sierra’s G1 BC is averaged for all speed ranges (which is representative of long range shooting) the results closely match the Applied Ballistics’ measurements of the same bullets, averaged from 3000 to 1500 FPS. The G7 BC doesn’t suffer nearly the velocity sensitivity as G1 and should be used for modern long range bullets when possible. Bryan tells us: “When I get the .22 caliber 77gr, and the .308 caliber 168gr tested, I’ll update the table.”
How do these Tipped MatchKings compare to standard MatchKings? According to Bryan’s measurements, here are some comparisons:
The 69gr TMK BC is +8% compared to the 69gr SMK
The 125gr TMK BC is -5% compared to the 125gr SMK (Litz believes this SMK was ‘pointed’)
The 155gr TMK BC is identical to that of the 155gr SMK (#2156, which is also pointed)
The 175gr TMK BC is +10% compared to the 175gr SMK
Bryan provided this additional advice for users of Ballistics programs: “Sierra’s stated BCs are measured by live fire, and are typically pretty accurate if the velocity bands are properly observed (7mm being the exception). A common error is to look at the BC that Sierra gives for your MV and just use that. Doing so overestimates the performance of the bullets over long range, and will cause you to hit low compared to your trajectory predictions.”
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Today is Friday the 13th. Oddly enough, this is the second month in a row with the 13th falling on a Friday. Does that mean double bad luck? For those of you who are superstitious — maybe you should avoid climbing ladders or using power tools today.
When it comes to shooting, there are many things that shooters chalk up to “bad luck”. In fact, most of these instances of “bad fortune” just come from a failure to anticipate problems. When you have a major, critical problem at a shooting match, i.e. a “train wreck”, this can be the end of your weekend. In this article, Ballistics Guru Bryan Litz talks about “train wrecks” and how to avoid them, even if you are shooting on Friday the 13th. As Bryan told us: “I don’t believe in superstition — we make our own luck!”
Urban Dictionary “Train Wreck” Definition: “A total @#$&! disaster … the kind that makes you want to shake your head.”
Success in long range competition depends on many things. Those who aspire to be competitive are usually detail-oriented, and focused on all the small things that might give them an edge. Unfortunately it’s common for shooters lose sight of the big picture — missing the forest for the trees, so to speak.
Consistency is one of the universal principles of successful shooting. The tournament champion is the shooter with the highest average performance over several days, often times not winning a single match. While you can win tournaments without an isolated stellar performance, you cannot win tournaments if you have a single train wreck performance. And this is why it’s important for the detail-oriented shooter to keep an eye out for potential “big picture” problems that can derail the train of success!
Train wrecks can be defined differently by shooters of various skill levels and categories. Anything from problems causing a miss, to problems causing a 3/4-MOA shift in wind zero can manifest as a train wreck, depending on the kind of shooting you’re doing.
Below is a list of common Shooting Match Train Wrecks, and suggestions for avoiding them.
1. Cross-Firing. The fastest and most common way to destroy your score (and any hopes of winning a tournament) is to cross-fire. The cure is obviously basic awareness of your target number on each shot, but you can stack the odds in your favor if you’re smart. For sling shooters, establish your Natural Point of Aim (NPA) and monitor that it doesn’t shift during your course of fire. If you’re doing this right, you’ll always come back on your target naturally, without deliberately checking each time. You should be doing this anyway, but avoiding cross-fires is another incentive for monitoring this important fundamental. In F-Class shooting, pay attention to how the rifle recoils, and where the crosshairs settle. If the crosshairs always settle to the right, either make an adjustment to your bipod, hold, or simply make sure to move back each shot. Also consider your scope. Running super high magnification can leave the number board out of the scope’s field view. That can really increase the risk of cross-firing.
2. Equipment Failure. There are a wide variety of equipment failures you may encounter at a match, from loose sight fasteners, to broken bipods, to high-round-count barrels that that suddenly “go south” (just to mention a few possibilities). Mechanical components can and do fail. The best policy is to put some thought into what the critical failure points are, monitor wear of these parts, and have spares ready. This is where an ounce of prevention can prevent a ton of train wreck. On this note, if you like running hot loads, consider whether that extra 20 fps is worth blowing up a bullet (10 points), sticking a bolt (DNF), or worse yet, causing injury to yourself or someone nearby.
3. Scoring/Pit Malfunction. Although not related to your shooting technique, doing things to insure you get at least fair treatment from your scorer and pit puller is a good idea. Try to meet the others on your target so they can associate a face with the shooter for whom they’re pulling. If you learn your scorer is a Democrat, it’s probably best not to tell Obama jokes before you go for record. If your pit puller is elderly, it may be unwise to shoot very rapidly and risk a shot being missed (by the pit worker), or having to call for a mark. Slowing down a second or two between shots might prevent a 5-minute delay and possibly an undeserved miss.
4. Wind Issues. Tricky winds derail many trains. A lot can be written about wind strategies, but here’s a simple tip about how to take the edge off a worse case scenario. You don’t have to start blazing away on the command of “Commence fire”. If the wind is blowing like a bastard when your time starts, just wait! You’re allotted 30 minutes to fire your string in long range slow fire. With average pit service, it might take you 10 minutes if you hustle, less in F-Class. Point being, you have about three times longer than you need. So let everyone else shoot through the storm and look for a window (or windows) of time which are not so adverse. Of course this is a risk, conditions might get worse if you wait. This is where judgment comes in. Just know you have options for managing time and keep an eye on the clock. Saving rounds in a slow fire match is a costly and embarrassing train wreck.
5. Mind Your Physical Health. While traveling for shooting matches, most shooters break their normal patterns of diet, sleep, alcohol consumption, etc. These disruptions to the norm can have detrimental effects on your body and your ability to shoot and even think clearly. If you’re used to an indoor job and eating salads in air-conditioned break rooms and you travel to a week-long rifle match which keeps you on your feet all day in 90-degree heat and high humidity, while eating greasy restaurant food, drinking beer and getting little sleep, then you might as well plan on daily train wrecks. If the match is four hours away, rather than leaving at 3:00 am and drinking five cups of coffee on the morning drive, arrive the night before and get a good night’s sleep.”
Keep focused on the important stuff. You never want to lose sight of the big picture. Keep the important, common sense things in mind as well as the minutia of meplat trimming, weighing powder to the kernel, and cleaning your barrel ’til it’s squeaky clean. Remember, all the little enhancements can’t make up for one big train wreck!
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More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.
Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:
Applied Ballistics used multiple barrels to study how twist rate affects BC.
“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz
Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.
The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.
It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.
To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.
Learn More About SG and BC This article is just a brief overview of the interrelated subjects of twist rate, Gyroscopic Stability, and BC. The coverage of twist rates in Modern Advancements in Long-Range Shooting is more detailed, with multiple live fire tests.
Other chapters in the book’s twist rate section include: · Stability and Drag – Supersonic
· Stability and Drag – Transonic
· Spin Rate Decay
· Effect of Twist rate on Precision
Other sections of the book include: Modern Rifles, Scopes, and Bullets as well as Advancements in Predictive Modeling. This book is sold through the Applied Ballistics online store. Modern Advancements in Long Range Shooting is also available in eBook format in the Amazon Kindle store.
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The Berger Southwest Nationals (SWN) kicked off Tuesday, February 10th, with an instructional clinic at the Ben Avery 1000-yard Range. This combined a lecture/Q&A session with live-fire training. Ballistics “Professor” Bryan Litz reports: “The clinic was a big hit as usual, with lots of competitor participation. There was a big crowd this year, as you can see.”
The clinic started with a class on Exterior Ballistics hosted by Bryan. This focused on why ballistics is important to competitive shooters, and how to balance ballistic performance objectives against real world constraints. Topics included bullet weight options for F-TR (155 to 215 grains), barrel/chamber considerations, plus the real-world trade-offs involved with heavy bullets (yes the BC may be better but recoil becomes an issue). Many of the questions related to content from Bryan’s recent books, and discussions in AccurateShooter.com’s Ballistics sub-Forum and Daily Bulletin.
Following the ballistics class, shooters made their way to the firing line for one-on-one instruction with experienced shooters in each discipline (sling, F-TR and F-Open). During this segment of the clinic, champion shooters worked directly with novice and intermediate shooters. Bryan said: “It was great to see the ‘top guns’ sharing their knowledge.”
Last but not least, Mid Tompkins directed a wind clinic with live fire demonstrations. Bryan reports: “Mid has a way of getting your attention. Personally, I thought his 2 MOA wind call that put the very first shot in the 5 inch X-ring at 1000 yards got everyone’s attention!” After the demonstrations, clinic “students” went to the firing line to put wind-clinic lessons into practice, and to verify their zeroes.
Mid Tompkins at the SWN Shooters’ Clinic
Here are some more images from the instructional clinic held last year at the 2014 SW Nationals.
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AccurateShooter.com has added something NEW to our Shooter’s Forum. We recently launched a new Ballistics & Bullets Board, with Bryan Litz as the “Guru in Residence”. Bryan and his team at Applied Ballistics will help answer your questions about bullet trajectories, wind drift, BC values, bullet sorting methods, meplat trimming/pointing, and other general ballistics matters. This is your chance to get your questions answered by Bryan, a expert ballistician, and an ace long-range shooter. In addition, our new Ballistics Forum area features free excerpts from Applied Ballistics’ respected publications, including Applied Ballistics for Long Range Shooting, and Bryan’s new book, Modern Advancements in Long Range Shooting. CLICK HERE for FREE Samples.
If you have a ballistics question, or are simply curious about subjects such as bullet pointing, trajectory prediction, ballistics programs, ballistic coefficients, etc., then visit our Shooters’ Forum and join the discussion in our new Ballistics & Bullets Board.
Get $5.00 Off Applied Ballistics Books
As a special benefit for AccurateShooter.com Forum members, Applied Ballistics is offering $5.00 off Books and DVDs. If you haven’t acquired one of Bryan’s books yet, here’s a way to get with the program and save five bucks in the process. CLICK HERE for $5.00 discount info.
Get Answers from the Man Who Literally
‘Wrote the Book’ on Ballistics…
As an aerospace engineer, Bryan worked six years for the government on air-to-air missile designs. He is now owner of Applied Ballistics and Chief Ballistician for Berger Bullets. Bryan is also a champion long range shooter, so he brings a great deal of practical knowledge and experience to the table regarding the science of accuracy.
A Place to Share Knowledge and Advance the Science of Ballistics Applied Ballistics is pleased to sponsor AccurateShooter.com’s new Ballistics & Bullets Board: “The new Ballistics Forum area provides an established place for shooters go and discuss ballistics-related issues in general. In addition to this basic objective of connecting shooters to each other, the staff of Applied Ballistics will frequent the Forum to provide expert advice on ballistics, and the use of ballistics programs. Bryan Litz will regularly visit the ballistics Forum, looking for ways to help shooters with ballistics questions. Beyond that, we’re eager to take suggestions on what kinds of tests we might consider for the AB Laboratory. We’re here to advance the science of ballistics, and we’d like to do that in ways that benefit the greatest amount of people. The ballistics forum gives us a place to explore these questions. We can answer the questions that we know, and formulate tests to explore those questions we don’t understand as well, then share the results online for everyone to see.”
How to Find the Ballistics & Bullets Board
To join in the discussions, visit our Shooters’ Forum. Scroll down until you see “Ballistics & Bullets Board, Presented by Bryan Litz and Applied Ballistics”. Just click on the orange title and you’re “in like Flynt”.
Guests can read all the topics. However, if you want to post or start a thread you’ll need to REGISTER with our Forum. There’s no charge (membership is FREE), and registration only takes a few minutes.
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