Here are two different bullet types, seated to the same CBTO length, but different COAL. Note the shiny scratches on the bullets made by the comparator tool which indicates a point on the bullet ogive near where the ogive will engage the rifling.
Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2 by Bryan Litz forBerger Bullets. Part One of this series focused on the importance of COAL in terms of SAAMI standards, magazine lengths, seating depths, and pressure levels. Another measure of length for loaded ammunition is highly important to precision, namely Cartridge Base to Bullet Ogive Length (CBTO).
Figure 2. Chamber throat geometry showing the bullet jump to the rifling or lands.
Look at Figure 2. Suppose the bullet was seated out of the case to the point where the base of the bullet’s nose (ogive) just contacted the beginning of the riflings (the lands) when the bolt was closed. This bullet seating configuration is referred to as touching the lands, or touching the riflings and is a very important measurement to understand for precision hand-loading. Due to the complex dynamics of internal ballistics which happen in the blink of an eye, the distance a bullet moves out of the case before it engages the riflings is highly critical to precision potential. Therefore, in order to systematically optimize the precision of his handloads, it’s critically important that the precision hand-loader understands how to alter bullet seating depth in relation to the barrel rifling. Part of the required knowledge is understanding how to accurately and repeatably measure the Cartridge Base To Ogive (CBTO) dimension. This is explained in the FULL ARTICLE.
Bryan Litz offers an extended discussion on how to measure CBTO using different tools and methods, including the Hornady OAL gauge. You can read this discussion in the full article found on the Berger Bullets website. CLICK HERE to Read Full Article.
Why Not Use CBTO as a SAAMI Standard?
If CBTO is so important to rifle accuracy, you might ask, “Why is it not listed as the SAAMI spec standard in addition to COAL?” There is one primary reason why it is not listed in the standard. This is the lack of uniformity in bullet nose shapes and measuring devices used to determine CBTO.
Benefits of Having a Uniform CBTO
There is another aspect to knowing your CBTO when checking your COAL as it pertains to performance. With good bullets, tooling, and carefully-prepared cases you can easily achieve a CBTO that varies less than +/- .001″ but your COAL can vary as much as .025″ extreme spread (or more with other brands). This is not necessarily bad and it is much better than the other way around. If you have a CBTO dimension that varies but your COAL dimension is tight (within +/- .002″) then it is most likely that your bullet is bottoming out inside the seater cone on the bullet tip. This is very bad and is to be avoided. It is normal for bullets to have precisely the same nose shape and it is also normal for these same bullets to have nose lengths that can vary as much as .025″.
Summary of Cartridge Base To Ogive (CBTO) Discussion
Here are four important considerations regarding bullet seating depth as it relates to CBTO:
1. CBTO is a critical measurement to understand for handloaders because it’s directly related to precision potential, and you control it by simply setting bullet seating depth.
2. Tools and methods for measuring CBTO vary. Most of the measurement techniques have pitfalls (which may give rise to inconsistent results) that you should understand before starting out.
3. A CBTO that produces the best precision in your rifle may not produce the best precision in someone else’s rifle. Even if you have the same rifle, same bullets, same model of comparator gauges, etc. It’s possible that the gauges are not actually the same, and measurements from one don’t translate to the same dimension for another.
4. Once you find the CBTO that produces the best precision in your rifle, it’s important to allow minimal variation in that dimension when producing quality handloads. This is achieved by using quality bullets, tooling, and properly preparing case mouths and necks for consistent seating.
Emil Praslick III is widely recognized as one of the greatest wind wizards on the planet — a master at identifying wind value and direction, and predicting wind cycles. As coach of the USAMU and top civilian teams, Emil has helped win many high-level championships. In the three videos we feature today, Emil, who works with Capstone Precision Group (Berger, Lapua, SK, Vihtavuori) and Team Applied Ballistics, explains how to determine wind direction and velocity using a variety of indicators. Praslick, now retired from the U.S. Army, was an 18-time National and 2-time World Champion coach with the USAMU.
Video ONE: Wind Theory Basics — Understanding “Wind Values”
In this video from UltimateReloader.com, Emil explains the basics of modern wind theory. To properly understand the effect of the wind you need to know both the velocity of the wind and its angle. The combination of those variables translates to the wind value. Emil also explains that the wind value may not be constant — it can cycle both in speed and velocity. Emil also explains some of the environmental conditions such as mirage that can reveal wind conditions.
Video TWO: Determining the Direction of the Wind
Key Point in Video — Find the Boil
Emil explains how to determine wind direction using optic. The method is to use spotting scope, riflescope, or binoculars to look for the “Boil” — the condition in mirage when the light waves rising straight up. The wind will generate that straight-up, vertical boil in your optics when it is blowing directly at you, or directly from your rear. To identify this, traverse your scope or optics until you see the boil running straight up. When you see that vertical boil, the direction your optic is pointing is aligned with the wind flow (either blowing towards you or from directly behind you).
Video THREE: The No Wind Zero Setting
In this second video, Emil defines the “No-Wind Zero”, and explains why competitive shooters must understand the no-wind zero and have their sights or optics set for a no-wind zero starting point before heading to a match. In order to hit your target, after determining wind speed and direction, says Emil, “you have to have your scope setting dialed to ‘no wind zero’ first.”
Coach of Champions — Emil Praslick III
SFC Emil Praslick III, (U.S. Army, retired) works with Berger Bullets and Applied Ballistics. Emil served as the Head Coach of the U.S. National Long Range Rifle Team and Head Coach of the USAMU for several years. Teams coached by Emil have won 33 Inter-Service Rifle Championships. On top of that, teams he coached set 18 National records and 2 World Records. Overall, in the role of coach, Praslick can be credited with the most team wins of any coach in U.S. Military history.
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Berger Twist-Rate Stability Calculator On the 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 cool tool tells you if your chosen bullet will really stabilize in your barrel.
How to Use Berger’s Twist Rate Calculator
Using the Twist Rate Calculator is simple. Just enter the bullet DIAMETER (e.g. .264), bullet WEIGHT (in grains), and bullet overall LENGTH (in inches). On its website, Berger conveniently provides this info for all its bullet types. For other brands, we suggest you weigh three examples of your chosen bullet, and also measure the length on three samples. Then use the average weight and length of the three. To calculate bullet stability, simply enter your bullet data (along with observed Muzzle Velocity, outside Temperature, and Altitude) and click “Calculate SG”. Try different twist rate numbers (and recalculate) until you get an SG value of 1.4 (or higher).
Gyroscopic Stability (SG) and Twist Rate
Berger’s Twist Rate Calculator provides a predicted stability value called “SG” (for “Gyroscopic Stability”). This indicates the Gyroscopic Stability applied to the bullet by spin. This number is derived from the basic equation: SG = (rigidity of the spinning mass)/(overturning aerodynamic torque).
If you have an SG under 1.0, your bullet is predicted not to stabilize. If you have between 1.0 and 1.1 SG, your bullet may or may not stabilize. If you have an SG greater than 1.1, your bullet should stabilize under optimal conditions, but stabilization might not be adequate when temperature, altitude, or other variables are less-than-optimal. That’s why Berger normally recommends at least 1.5 SG to get out of the “Marginal Stability” zone.
In his book Applied Ballistics For Long-Range Shooting (3rd Ed.), Bryan Litz (Berger Ballistician) recommends at least a 1.4 SG rating when selecting a barrel twist for a particular bullet. This gives you a safety margin for shooting under various conditions, such as higher or lower altitudes or temperatures.
Story idea from EdLongrange. We welcome reader submissions.
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In discussions of ballistics, you’ll see references to “tangent”, “secant”, and “hybrid” bullet shapes. We know that, for many readers, these terms can be confusing. To add to the confusion, bullet makers don’t always identify their projectiles as secant or tangent designs. This article provides a basic explanation of tangent, secant, and hybrid ogive bullet designs, to help you understand the characteristics of these three basic bullet shapes.
Tangent vs. Secant vs. Hybrid
Most match bullets produced today use a tangent ogive profile, but the modern VLD-style bullets employ a secant profile. To further complicate matters, the latest generation of “Hybrid” projectiles from Berger Bullets feature a blended secant + tangent profile to combine the best qualities of both nose shapes. The secant section provides reduced drag, while the tangent section makes the bullet easier to tune, i.e. less sensitive to bullet seating depth position.
Berger Bullets ballistician Bryan Litz explains tangent and secant bullet ogive designs in a glossary section of his Applied Ballistics website, which we reprint below. Bryan then explains how tangent and secant profiles can be combined in a “hybrid” design.
How Bullet Ogive Curves are Defined
While the term “ogive” is often used to describe the particular point on the bullet where the curve reaches full bullet diameter, in fact the “ogive” properly refers to the entire curve of the bullet from the tip to the full-diameter straight section — the shank.
Understanding then, that the ogive is a curve, how is that curve described?
LITZ: The ogive of a bullet is usually characterized by the length of its radius. This radius is often given in calibers instead of inches. For example, an 8 ogive 6mm bullet has an ogive that is a segment of a circular arc with a radius of 8*.243 = 1.952”. A .30-caliber bullet with an 8 ogive will be proportionally the same as the 8 ogive 6mm bullet, but the actual radius will be 2.464” for the .30 caliber bullet.
For a given nose length, if an ogive is perfectly tangent, it will have a very specific radius. Any radius longer than that will cause the ogive to be secant. Secant ogives can range from very mild (short radius) to very aggressive (long radius). The drag of a secant ogive is minimized when its radius is twice as long as a tangent ogive radius. In other words, if a tangent ogive has an 8 caliber radius, then the longest practical secant ogive radius is 16 calibers long for a given nose length.”
Bryan Litz Explains Hybrid Design and Optimal Hybrid Seating Depths
Ogive Metrics and Rt/R Ratio
LITZ: There is a number that’s used to quantify how secant an ogive is. The metric is known as the Rt/R ratio and it’s the ratio of the tangent ogive radius to the actual ogive radius for a given bullet. In the above example, the 16 caliber ogive would have an Rt/R ratio of 0.5. The number 0.5 is therefore the lowest practical value for the Rt/R ratio, and represents the minimum drag ogive for a given length. An ogive that’s perfectly tangent will have an Rt/R ratio of 1.0. Most ogives are in between an Rt/R of 1.0 and 0.5. The dimensioned drawings at the end of my Applied Ballistics book provide the bullets ogive radius in calibers, as well as the Rt/R ratio. In short, the Rt/R ratio is simply a measure of how secant an ogive is. 1.0 is not secant at all, 0.5 is as secant as it gets.
Hybrid Bullet Design — Best of Both Worlds?
Bryan Litz has developed a number of modern “Hybrid” design bullets for Berger. The objective of Bryan’s design work has been to achieve a very low drag design that is also “not finicky”. Normal (non-hybrid) secant designs, such as the Berger 105gr VLD, deliver very impressive BC values, but the bullets can be sensitive to seating depth. Montana’s Tom Mousel has set world records with the Berger 105gr VLD in his 6mm Dasher, but he tells us “seating depth is critical to the best accuracy”. Tom says a mere .003″ seating depth change “makes a difference”. In an effort to produce more forgiving high-BC bullets, Bryan Litz developed the hybrid tangent/secant bullet shape.
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Berger Twist-Rate Stability Calculator On the 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 cool tool tells you if your chosen bullet will really stabilize in your barrel.
How to Use Berger’s Twist Rate Calculator
Using the Twist Rate Calculator is simple. Just enter the bullet DIAMETER (e.g. .264), bullet WEIGHT (in grains), and bullet overall LENGTH (in inches). On its website, Berger conveniently provides this info for all its bullet types. For other brands, we suggest you weigh three examples of your chosen bullet, and also measure the length on three samples. Then use the average weight and length of the three. To calculate bullet stability, simply enter your bullet data (along with observed Muzzle Velocity, outside Temperature, and Altitude) and click “Calculate SG”. Try different twist rate numbers (and recalculate) until you get an SG value of 1.4 (or higher).
Gyroscopic Stability (SG) and Twist Rate
Berger’s Twist Rate Calculator provides a predicted stability value called “SG” (for “Gyroscopic Stability”). This indicates the Gyroscopic Stability applied to the bullet by spin. This number is derived from the basic equation: SG = (rigidity of the spinning mass)/(overturning aerodynamic torque).
If you have an SG under 1.0, your bullet is predicted not to stabilize. If you have between 1.0 and 1.1 SG, your bullet may or may not stabilize. If you have an SG greater than 1.1, your bullet should stabilize under optimal conditions, but stabilization might not be adequate when temperature, altitude, or other variables are less-than-optimal. That’s why Berger normally recommends at least 1.5 SG to get out of the “Marginal Stability” zone.
In his book Applied Ballistics For Long-Range Shooting (3rd Ed.), Bryan Litz (Berger Ballistician) recommends at least a 1.4 SG rating when selecting a barrel twist for a particular bullet. This gives you a safety margin for shooting under various conditions, such as higher or lower altitudes or temperatures.
Story idea from EdLongrange. We welcome reader submissions.
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Ever wondered how factory ammunition is produced, from start to finish? How are brass cases made, how are bullets created, and how are finished cartridges produced on automated assembly lines? Today’s video showcase features six major factories that, collectively, produce bullets, powder, and finished ammo. We start with the Berger Bullet plant, follow by Vihtavuori powder production in Europe. Then we show the Remington (now Vista Outdoor) ammo plant in Utah, along with a Federal plant that produces rimfire ammunition. Last but not least, there’s an excellent, very informative video from the Norma ammo factory, plus a Hornady ammo plant video.
Bullets being seating at Hornady ammo factory.
Berger Bullets Factory Tour — Made in USA
In this video, Recoil TV takes a behind-the-scenes look at Berger Bullets, and how the outstanding, match-winning Berger bullets are created. The video covers the entire process — from raw materials, to the placement of bullet cores inside jackets, to the final ultra-consistent and uniform projectiles. To see the complete line of Berger Bullets, with full Ballistic data, visit BergerBullets.com
Vihtavuori Powder Production in Europe
Vihtavuori produces some of the most consistent, high-quality powder on the planet. Vihtavuori powders have been used to set world records and win countless championships in multiple disciplines. This excellent video goes inside Vihtavuori’s European production centers. It is really fascinating — you see how extruded powder starts with long spaghetti-like strings, before being finalized into the tiny sticks that we load.
Along with the powder production process, this video includes the entire VV production line, so you see how powder bottles are filled with powder and the tops of the bottles are secured by automated machines.
Remington Ammo Factory (Now Operated by Vista Outdoor)
This SHWATteam video visits the Remington ammunition plant in Arkansas. Vista Outdoor, the company that produces Federal, Speer and CCI ammo, purchased Remington’s ammunition business in Lonoke, Arkansas. Including the new high-tech plant in the back, this facility has the equivalent of 13+ football fields (1200 acres) under roof at its ammo plant, with over 1100 employees. Production capacity is impressive. When running at maximum output, this Remington ammo plant can crank out a staggering 7,000,000+ rounds every day. To produce that volume of ammunition, the facility needs a huge amount of resources: one million pounds of copper per month and 124,000 pounds of lead per day. Remington started manufacturing ammunition at this Lonoke facility in 1970, but some of the machines have been churning out ammo since long before.
Norma Factory Tour
Guys — honestly, if you do anything today on this site, watch this video. You won’t be disappointed. Guaranteed. This is a very informative (and surprisingly entertaining) video. Every serious hand-loader should watch this video to see how cartridge cases are made. The camera work and editing are excellent — there are many close-ups revealing key processes such as annealing and head-stamping.
VERY Informative Video Show Cartridge Brass and Ammunition Production:
Norma has released a fascinating video showing how bullets, brass, and ammunition are produced at the Norma Precision AB factory which opened in 1902. You can see how cartridges are made starting with brass disks, then formed into shape through a series of processes, including “hitting [the cup] with a 30-ton hammer”. After annealing (shown at 0:08″), samples from every batch of brass are analyzed to check metal grain structure and hardness. Before packing, each case is visually inspected by a human being (3:27″ time-mark).
Federal Rimfire Ammunition Production
Field & Stream Tours Federal Ammo Plant in Minnesota
A reporter for Field & Stream recently got a chance to tour the Federal ammunition production facility in Anoka, Minnesota. This large plant produces both rimfire and centerfire ammunition. While touring the plant, the reporter was allowed to capture video showing the creation of .22 LR rounds from start to finish. This is a fascinating video, well worth watching. Watch and learn how rimfire ammo is made.
Note to Viewers — After Starting Video, Click Speaker Icon to HEAR audio!
This revealing video shows all phases of .22 LR ammo production including cupping, drawing, annealing, washing, drying, head-stamping, priming, powder charging, bullet seating, crimping, waxing, inspection, and final packaging. We recommend you watch the video from start to finish. You’ll definitely learn some new things about rimfire ammo.
Hornady Ammunition Factory
If you wonder how ammo is made, starting with raw metal, check out this video from Hornady. It shows how bullet jackets are formed from copper, followed by insertion of a lead core. The jacket is then closed up over the core with the bullet taking its final shape in a die (a cannelure is applied on some bullet types). Next the video shows how cartridge brass is formed, starting with small cups of brass. The last part of the video shows how cases are primed and filled with powder, and how bullets are seated into the cases, using an automated process on a giant assembly-line.
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Here are two different bullet types, seated to the same CBTO length, but different COAL. Note the shiny scratches on the bullets made by the comparator tool which indicates a point on the bullet ogive near where the ogive will engage the rifling.
Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2 by Bryan Litz forBerger Bullets. Part One of this series focused on the importance of COAL in terms of SAAMI standards, magazine lengths, seating depths, and pressure levels. Another measure of length for loaded ammunition is highly important to precision, namely Cartridge Base to Bullet Ogive Length (CBTO).
Figure 2. Chamber throat geometry showing the bullet jump to the rifling or lands.
Look at Figure 2. Suppose the bullet was seated out of the case to the point where the base of the bullet’s nose (ogive) just contacted the beginning of the riflings (the lands) when the bolt was closed. This bullet seating configuration is referred to as touching the lands, or touching the riflings and is a very important measurement to understand for precision hand-loading. Due to the complex dynamics of internal ballistics which happen in the blink of an eye, the distance a bullet moves out of the case before it engages the riflings is highly critical to precision potential. Therefore, in order to systematically optimize the precision of his handloads, it’s critically important that the precision hand-loader understands how to alter bullet seating depth in relation to the barrel rifling. Part of the required knowledge is understanding how to accurately and repeatably measure the Cartridge Base To Ogive (CBTO) dimension. This is explained in the FULL ARTICLE.
Bryan Litz offers an extended discussion on how to measure CBTO using different tools and methods, including the Hornady OAL gauge. You can read this discussion in the full article found on the Berger Bullets website. CLICK HERE to Read Full Article.
Why Not Use CBTO as a SAAMI Standard?
If CBTO is so important to rifle accuracy, you might ask, “Why is it not listed as the SAAMI spec standard in addition to COAL?” There is one primary reason why it is not listed in the standard. This is the lack of uniformity in bullet nose shapes and measuring devices used to determine CBTO.
Benefits of Having a Uniform CBTO
There is another aspect to knowing your CBTO when checking your COAL as it pertains to performance. With good bullets, tooling, and carefully-prepared cases you can easily achieve a CBTO that varies less than +/- .001″ but your COAL can vary as much as .025″ extreme spread (or more with other brands). This is not necessarily bad and it is much better than the other way around. If you have a CBTO dimension that varies but your COAL dimension is tight (within +/- .002″) then it is most likely that your bullet is bottoming out inside the seater cone on the bullet tip. This is very bad and is to be avoided. It is normal for bullets to have precisely the same nose shape and it is also normal for these same bullets to have nose lengths that can vary as much as .025″.
Summary of Cartridge Base To Ogive (CBTO) Discussion
Here are four important considerations regarding bullet seating depth as it relates to CBTO:
1. CBTO is a critical measurement to understand for handloaders because it’s directly related to precision potential, and you control it by simply setting bullet seating depth.
2. Tools and methods for measuring CBTO vary. Most of the measurement techniques have pitfalls (which may give rise to inconsistent results) that you should understand before starting out.
3. A CBTO that produces the best precision in your rifle may not produce the best precision in someone else’s rifle. Even if you have the same rifle, same bullets, same model of comparator gauges, etc. It’s possible that the gauges are not actually the same, and measurements from one don’t translate to the same dimension for another.
4. Once you find the CBTO that produces the best precision in your rifle, it’s important to allow minimal variation in that dimension when producing quality handloads. This is achieved by using quality bullets, tooling, and properly preparing case mouths and necks for consistent seating.
Over the past 12 months, this article was one of the TOP 20 most-read Daily Bulletin features. We’re reprising it today for those who may have missed it the first time. The above diagram comes from a TiborasurasRex YouTube Video comparing G1 and G7 BC models. CLICK HERE to watch the video.
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 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 preferable 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.]
This article is copyright 2023 AccurateShooter.com. No 3rd Party republication of this article is allowed without advance approval and payment of licensing fees.
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At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
NOTE: All listed products are for sale to persons 18 years of age or older. No products are intended for use by minors.
1. Brownells — Weekly Featured Deals and Memorial Day Sale
⏺ Great deals at Brownells — ammo, bullets, optics, chronos, and more
2. EuroOptic — 50% Off Vortex for Military, LE, First Responders
⏺ 50% Off MSRP for Military, police, first responders through 5/30/24
Today (5/27/24) is Memorial Day. To help mark this day, Vortex, via EuroOptic, has a special promotion with 50% off MSRP for Vortex products. This offer runs through May 30, 2024. After that a similar Military/LE/First Responder discount may be available at 40% off MSRP. CLICK HERE for more information. To qualify you must set up a user account. The offer excludes close-outs and discontinued items.
3. Primary Arms — Memorial Day Sale, Save up to 30%
⏺ Major savings on hundreds of items — great for AR components
Primary Arms is running a big Memorial Day Sale with hundreds of items on Sale. Along with the featured special, you can shop for deals by Manufacturer/Brand (e.g. Vortex, EoTech, Magpul) or by Product Category (e.g. Optics, Barrels, Ammo, AR Uppers). Shown above are four noteworthy deals, but there are over 2000 items discounted.
4. Midsouth — Peterson Brass on Sale, 24 Varieties
⏺ High quality, long lasting brass — good PRS/NRL choice
Excellent American-made Peterson brass is on sale now at Midsouth. You’ll find many 6mm options including 6mm Dasher and 6mm Creedmoor. If you shoot a Dasher, this Peterson brass will let you avoid the time and expense of fire-forming cases. Hunters will be pleased to find a number of large magnum cartridge types available including 7mm PRC, 7mm RUM, .300 WinMag, .300 Norma Mag, 33 Nosler, .338 Lapua Magnum, and more.
5. MidwayUSA — ATN Day/Night 3-14X Video Scope, $559.00
⏺ Advanced scope records video and operates daytime and night-time
Here’s a great electro-optics product for hunters. The 3-14X ATN X-Sight scope offers day/night viewing capability, PLUS it can record HD video of your hunt. This scope even has a built-in Ballistics Calculator that shows hold-overs. Right now this 3-14X optic is $559.00 at MidwayUSA, a $140.00 (20%) discount. In addition to the ATN 3-14X model, there is a 5-20X version for $639.00 on sale at Midway USA. Both models offer HD video recording, ballistics, electronic compass, multiple reticle options, and smartphone connectivity. BONUS: Both 3-14X and 5-20X ATN optics ship with 30mm Picatinny rings.
6. Creedmoor Sports — Berger 6mm, 6.5mm, 7mm Bullets Sale
⏺ Good prices on top-tier Berger match bullets
Berger bullets are favored by top competitors in many disciplines. Right now you can get significant savings on popular Berger match bullets in 6mm, 6.5mm, and 7mm calibers. F-Class shooters — take note that Berger 180gr Match Hybrid Target bullets and 184gr F-Open Hybrid Target bullets are on sale — save $10 per hundred. Along with the savings on top-tier bullets, through 5/28/24 you can get FREE Shipping with orders over $149.00. Use Creedmoor Sports discount code REMEMBER.
7. Amazon — Lyman BrassSmith Funnel, $31.99
⏺ Very useful kit we use — avoids powder spills
Having a good powder funnel really helps precision reloading. The Lyman Products Brass Smith Pro Powder Funnel System (#ad) is a great little system. Unlike plastic powder funnels, the aluminum DIE cast body and CNC-turned aluminum caliber-specific inserts are static free to eliminate powder cling. The precision fit to your case necks eliminates spilled powder. The kit includes six laser-marked aluminum inserts to fit calibers 22 to 338: .22, .243/6mm, .25/6.5mm, .270/7mm, .30, and .338.
8. Midsouth — CCI Blazer .22 LR Ammo, $32.99/500 Rounds
⏺ Very low price on good, reliable .22 LR ammunition
If you use .22 LR ammo for NRL22, varminting, or plinking, consider this CCI Blazer 40gr ammunition. Rated at 1235 fps, this CCI ammo runs pretty fast and packs a punch. Right now you can get a 500-ct brick for just $32.99. That’s just $3.29 per 50-ct box, a great value for quality American-made ammo.
9. MidwayUSA — Plano Protector Pro-Max Rifle Case, $33.99
⏺ Good price on a sturdy, 52″ interior transport case for long rifles
Do you have a long-barreled hunting or varmint rifle? With a 52″ internal size, this Plano Protector Pro-Max Rifle Case handles rifles with barrels up to 30″ (or 31″ with a thin buttplate). On the inside the case has high-density, interlocking foam padding. On the outside, the case has four clamps, padlock tabs, and a handy carry handle. NOTE: This case will work well for normal trips to the range. However, you’ll want a thicker, more sturdy TSA-approved case for airline transport.
⏺ Under $20 for versatile, multi-lens Eye Protection
All shooters need quality eye protection when operating firearms. XAegis Tac Eyewear is a versatile and affordable option. These ANSI Z87+ rated shooting glasses come with three different interchangeable lenses (Clear, Yellow, Gray). You also get a transport case, lanyard, and cleaning cloth. Choose from three frame colors, each for $18.99: Black frame, Green Frame, or Khaki frame. For under $20 these are hard to beat. It’s nice to have the color lens options for different weather conditions, and indoors/outdoors.
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Berger Twist-Rate Stability Calculator
On the 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 cool tool tells you if your chosen bullet will really stabilize in your barrel.
How to Use Berger’s Twist Rate Calculator
Using the Twist Rate Calculator is simple. Just enter the bullet DIAMETER (e.g. .264), bullet WEIGHT (in grains), and bullet overall LENGTH (in inches). On its website, Berger conveniently provides this info for all its bullet types. For other brands, we suggest you weigh three examples of your chosen bullet, and also measure the length on three samples. Then use the average weight and length of the three. To calculate bullet stability, simply enter your bullet data (along with observed Muzzle Velocity, outside Temperature, and Altitude) and click “Calculate SG”. Try different twist rate numbers (and recalculate) until you get an SG value of 1.4 (or higher).
Gyroscopic Stability (SG) and Twist Rate
Berger’s Twist Rate Calculator provides a predicted stability value called “SG” (for “Gyroscopic Stability”). This indicates the Gyroscopic Stability applied to the bullet by spin. This number is derived from the basic equation: SG = (rigidity of the spinning mass)/(overturning aerodynamic torque).
If you have an SG under 1.0, your bullet is predicted not to stabilize. If you have between 1.0 and 1.1 SG, your bullet may or may not stabilize. If you have an SG greater than 1.1, your bullet should stabilize under optimal conditions, but stabilization might not be adequate when temperature, altitude, or other variables are less-than-optimal. That’s why Berger normally recommends at least 1.5 SG to get out of the “Marginal Stability” zone.
In his book Applied Ballistics For Long-Range Shooting, 3rd Ed., Bryan Litz (Berger Ballistician) recommends at least a 1.4 SG rating when selecting a barrel twist for a particular bullet. This gives you a safety margin for shooting under various conditions, such as higher or lower altitudes or temperatures.
Story idea from EdLongrange. We welcome reader submissions.
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Guest Article By Michelle Gallagher, Berger Bullets
Let’s face it. In the world of firearms, there is something for everyone. Do you like to compete? Are you a hunter? Are you more of a shotgun shooter or rifle shooter? Do you enjoy running around between stages of a timed course, or does the thought of shooting one-hole groups appeal to you more? Even though many of us shoot several different firearms and disciplines, chances are very good that we all have a favorite. Are we spreading ourselves too thin by shooting different disciplines, or is it actually beneficial? I have found that participating in multiple disciplines can actually improve your performance. Every style of shooting is different; therefore, they each develop different skills that benefit each other.
How can cross-training in other disciplines help you? For example, I am most familiar with long-range prone shooting, so let’s start there. To be a successful long-range shooter, you must have a stable position, accurate ammunition, and good wind-reading skills. You can improve all of these areas through time and effort, but there are other ways to improve more efficiently. Spend some time practicing smallbore. Smallbore rifles and targets are much less forgiving when it comes to position and shot execution. Long-range targets are very large, so you can get away with accepting less than perfect shots. Shooting smallbore will make you focus more on shooting perfectly center shots every time. Another way to do this with your High Power rifle is to shoot on reduced targets at long ranges. This will also force you to accept nothing less than perfect. Shoot at an F-Class target with your iron sights. At 1000 yards, the X-Ring on a long range target is 10 inches; it is 5 inches on an F-Class target. Because of this, you will have to focus harder on sight alignment to hit a center shot. When you go back to the conventional target, you will be amazed at how large the ten ring looks.
Also, most prone rifles can be fitted with a bipod. Put a bipod and scope on your rifle, and shoot F-TR. Shooting with a scope and bipod eliminates position and eyesight factors, and will allow you to concentrate on learning how to more accurately read the wind. The smaller target will force you to be more aggressive on your wind calls. It will also help encourage you to use better loading techniques. Nothing is more frustrating than making a correct wind call on that tiny target, only to lose the point out the top or bottom due to inferior ammunition. If you put in the effort to shoot good scores on the F-Class target, you will be amazed how much easier the long-range target looks when you return to your sling and iron sights. By the same token, F-Class shooters sometimes prefer to shoot fast and chase the spotter. Shooting prone can help teach patience in choosing a wind condition to shoot in, and waiting for that condition to return if it changes.
Benchrest shooters are arguably among the most knowledgeable about reloading. If you want to learn better techniques about loading ammunition, you might want to spend some time at benchrest matches. You might not be in contention to win, but you will certainly learn a lot about reloading and gun handling. Shooting F-Open can also teach you these skills, as it is closely related to benchrest. Benchrest shooters may learn new wind-reading techniques by shooting mid- or long-range F-Class matches.
Position shooters can also improve their skills by shooting different disciplines. High Power Across-the-Course shooters benefit from shooting smallbore and air rifle. Again, these targets are very small, which will encourage competitors to be more critical of their shot placement. Hunters may benefit from shooting silhouette matches, which will give them practice when shooting standing with a scoped rifle. Tactical matches may also be good, as tactical matches involve improvising shots from various positions and distances. [Editor: Many tactical matches also involve hiking or moving from position to position — this can motivate a shooter to maintain a good level of general fitness.]
These are just a few ways that you can benefit from branching out into other shooting disciplines. Talk to the other shooters. There is a wealth of knowledge in every discipline, and the other shooters will be more than happy to share what they have learned. Try something new. You may be surprised what you get out of it. You will certainly learn new skills and improve the ones you already have. You might develop a deeper appreciation for the discipline you started off with, or you may just discover a new passion.
This article originally appeared in the Berger Blog. The Berger Blog contains the latest info on Berger products, along with informative articles on target shooting and hunting.
Article Find by EdLongrange.
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Applied Ballistics Founder Bryan Litz and Former USAMU and Team USA coach Emil Praslick III share their wisdom in an informative Guns Magazine Podcast. Along with being a true ballistics guru, Bryan Litz is an outstanding competitive shooter, having won F-TR National Championships, and both Sling and F-TR divisions at the Berger SW Nationals, along with many other matches. Emil is considered one of the world’s great wind-readers and team coaches, having coached 20+ championship teams.
Guns Magazine podcast host Brent Wheat asks Bryan and Emil about multiple topics including: exterior ballistics, bullet design, wind reading, ballistic solvers, BC myths, and more.
Brent reports: “Together, Bryan and Emil understand what happens from the time a bullet leaves the muzzle until it impacts the target, including the atmospheric affects along the way. Grab a pencil, listen in, and get ready to take notes.”
This Long Range Grad School podcast features Berger’s Chief Ballistician, Bryan Litz, and Berger’s Emil Praslick. Both have extensive long range competitive shooting experience, with championship titles (as shooter and/or coach) in a multitude of long range disciplines. CLICK arrow below to start podcast audio:
Emil Praslick (left) confers with Bryan Litz (right) at King of 2 Miles ELR Event.
In this Video Emil Praslick explains his methods for determining wind direction.
Bryan Litz coaching Team USA in Canada using a WIND PLOT.
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Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2
Hybrid Bullet Design — Best of Both Worlds?
Norma has released a fascinating video showing how bullets, brass, and ammunition are produced at the 
If you wonder how ammo is made, starting with raw metal, check out this video from 
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.
Drag Models — G7 is better than G1 for Long-Range Bullets
Position shooters can also improve their skills by shooting different disciplines. High Power Across-the-Course shooters benefit from shooting smallbore and air rifle. Again, these targets are very small, which will encourage competitors to be more critical of their shot placement. Hunters may benefit from shooting silhouette matches, which will give them practice when shooting standing with a scoped rifle. Tactical matches may also be good, as tactical matches involve improvising shots from various positions and distances. [Editor: Many tactical matches also involve hiking or moving from position to position — this can motivate a shooter to maintain a good level of general fitness.]
