Kestrel wind and weather meters are often regarded as the best on the market — for good reason. Here are a series of three videos by F-Class John that show how the Kestrel 5700 with Elite Ballistics works. This article reviews the advanced Kestrel 5700 Elite Wind Meter with sophisticated ballistics capabilities. Our review features three videos by F-Class John that show how the Kestrel 5700 Elite functions with Applied Ballistics APP software and LiNK connection.
This Part I Video starts with a basic Kestrel Anemometer (blue case, 00:00-00:40) wind meter. Then reviewer F-Class John looks at the “smart” Kestrel 5700 with Elite Ballistics. John explains the many features of the Kestrel 5700 and how it holds a powerful ballistics calculator in the convenient, easy-to-tote Kestrel package. With Elite Ballistics, once you enter data about your bullets, velocity, zero, and rifle, the Kestrel can calculate come-ups and wind corrections. If you don’t yet own a Kestrel, we highly recommend you watch this series of videos that explains advanced Kestrel features in detail.
This Part II Video shows the key features of the advanced software APP used by the Kestrel 5700 unit with Elite Ballistics. The Kestrel 5700 can “talk” to a mobile device that runs the Applied Ballistics software APP that contains bullet databases and allows you to enter key information such as muzzle velocity, bullet BC, zero distance, velocity, wind, and environmental factors (altitude, temperature etc.). There are also gun-specific factors such as scope height over bore and barrel twist rate. The video also explains how “range cards” are created and how to view them with your Elite Ballistics-enabled Kestrel. John notes: “The APP is great because you don’t have to fiddle with the Kestrel’s buttons. It’s much easier to enter data and change settings with the APP.”
This Part III video shows how to determine true wind direction by aligning the SIDE of the unit into the wind. You essentially want to set the unit 90 degrees to the wind direction so the impeller runs as slowly as possible. Then, after you set your target distance (See 3:03), the unit can give you precise come-ups for your intended target (10.28 MOA for 559 yards here). The Kestrel then calculates the cross-wind correction as well (See 3:12).
DISCLAIMER: This video and description contains affiliate links, which means that if you click on one of the product links, the video author may receive a small commission. This helps support F-Class John’s YouTube channel and allows him to continue to make videos like this.
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Here’s a smart tip from Bryan Litz, explaining how damage to a bullet jacket can harm the projectile’s Ballistic Coefficient (BC). This tip is posted on Bryan’s new Bryan Litz Ballistics Facebook page. We recommend you subscribe to that page to access Bryan’s latest informative posts.
Bryan notes: “If the case mouth scratches the bullet when you seat it, the damage can cause the BC to be inconsistent, which shows up as vertical dispersion at long range.”
We see this sometimes when running Doppler Radar for competitors at Applied Ballistics Mobile Lab events. If someone is shooting a bullet that typically has a very consistent BC (1% or less) but they’re seeing a higher BC variation, it can be due to the bullets being damaged in the loading process.”
The lead photo above shows the badly-scratched jacket of a bullet seated in a rough-mouthed case. To prevent such jacket damage, one should chamfer, deburr, and smooth case mouths after trimming.
Below is a recorded Doppler radar result showing excessive BC variation. Such variation can increase vertical dispersion at long range. This can result in larger group sizes and lower scores.
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Kestrel Ballistics will host a live Q&A session with four leading industry professionals at its SHOT Show exhibitor booth #14856. The expert panel session will take place today January 19th from 1:00 to 2:00 pm MST. The 4-man panel includes respected ballistics and shooting experts: Bryan Litz, Mitchell Fitzpatrick, Todd Hodnett, and Colby Hodnett. These four men will take questions from attendees and share their advanced knowledge of ballistics, ELR competition, and all things shooting related.
Bryan Litz earned his Aerospace Engineering degree from Pennsylvania State University in 2002. For the next six years, he worked for the U.S. Air Force on air-to-air missile design and simulation. In 2008, he left the USAF to become Chief Ballistician for Berger Bullets. Bryan then founded Applied Ballistics and has produced numerous articles, books, and videos related to the science of long-range shooting. Bryan also has notable competition credits including winning the 2015 Mid-Range F-TR National Championship. The author of leading books on ballistics and long-range shooting, Bryan is widely considered the leading rifle ballistics expert on the planet.
Mitchell Fitzpatrick is an engineer with Applied Ballistics. Mitch’s shooting accomplishments range from Junior F-TR World Champion in 2013 to winning the 2016 King of 2 Miles ELR shooting competition. He also won the Open Division at the 2019 Nightforce ELR Match. After graduating from Michigan Technological University with a major in Mechanical Engineering and minor in Aerospace Engineering, Mitch joined the Applied Ballistics team in 2014. Mitchell is now a full-time engineer with Applied Ballistics.
Mitchell Fitzpatrick shooting .375 EnABELR in an ELR Competition..
Todd Hodnett, President of Accuracy 1st, is considered one of the most respected and sought-after instructors in the entire world. With 20 years of experience, Todd has traveled the world training soldiers in the art of precision shooting. His determination, knowledge, and vision have guided the development of products to improve the accuracy and function of the sniper and precision shooter.
Colby Hodnett works as a long-range instructor with Accuracy 1st. In addition to being an avid hunter, angler, and outdoor enthusiast, Colby is a Commercial helicopter pilot, certified flight instructor, NRA-certified pistol instructor, and aircraft mechanic. Colby, along with his father Todd, continue to serve the Kestrel community by being a resource for all-things long-range shooting.
Visit the Kestrel Booth Today at 1:00 PM
Don’t miss your shot to talk with these pros! Swing by Booth #14856 January 19th from 1:00 to 2:00 PM. The four-man panel also previously held sessions at the Kestrel Booth on January 17th and 18th. But today is the last opportunity for SHOT Show attendees to hear the panel.
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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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Many barrel-makers mark the twist rate and bore dimensions on their barrel blanks.
Does muzzle velocity change with faster or slower barrel twist rates? Absolutely, but much less than you might think. Faster twist rates do slow down bullets somewhat, but the speed loss is NOT that significant. With Bartlein .308 Win barrels of identical length and contour, a 1:12″-twist barrel was only 8 fps faster than a 1:8″-twist barrel. That was the result of testing by Applied Ballistics.
The Applied Ballistics team tested six (6) same-length/same-contour Bartlein barrels to observe how twist rate might affect muzzle velocity. This unique, multi-barrel test is featured in the book Modern Advancements in Long Range Shooting, Vol. 1. That book includes other fascinating field tests, including a comprehensive chronograph comparison.
Barrel Twist Rate vs. Velocity — What Tests Reveal by Bryan Litz
When considering barrel twist rates, it’s a common belief that faster twist rates will reduce muzzle velocity. The thinking is that the faster twist rate will resist forward motion of the bullet and slow it down. There are anecdotal accounts of this, such as when someone replaces a barrel of one brand/twist with a different brand and twist and observes a different muzzle velocity. But how do you know the twist rate is what affected muzzle velocity and not the barrel finish, or bore/groove dimensions? Did you use the same chronograph to measure velocity from both barrels? Do you really trust your chronograph?
Summary of Test Results
After all the smoke cleared, we found that muzzle velocity correlates to twist rate at the average rate of approximately 1.33 FPS per inch of twist. In other words, your velocity is reduced by about 5 FPS if you go from a 1:12″ twist to a 1:8″ twist. — Bryan Litz
Savage Test Rifle with Six Bartlein Barrels
Most shooters don’t have access to the equipment required to fully explore questions like this. These are exactly the kinds of things we examine in the book Modern Advancements in Long Range Shooting, Vol. 1. In that book, we present experiments conducted in the Applied Ballistics lab. Some of those experiments took on a “Myth Buster” tone as we sought to confirm (or deny) popular pre-conceptions. For example, here’s how we approached the question of barrel twist and muzzle velocity.
Six .308 Win Barrels from Bartlein — All Shot from the Same Rifle
We acquired six (6) barrels from the same manufacturer (Bartlein), all the same length and contour, and all chambered with the same reamer (SAAMI spec .308 Winchester). All these barrels were fitted to the same Savage Precision Target action, and fired from the same stock, and bench set-up. Common ammo was fired from all six barrels having different twist rates and rifling configurations. In this way, we’re truly able to compare what effect the actual twist rate has on muzzle velocity with a reasonable degree of confidence.
Prior to live fire testing, we explored the theoretical basis of the project, doing the physics. In this case, an energy balance is presented which predicts how much velocity you should expect to lose for a bullet that’s got a little more rotational energy from the faster twist. In the case of the .30 caliber 175 grain bullets, the math predicts a loss of 1.25 fps per inch-unit of barrel twist (e.g. a 1:8″ twist is predicted to be 1.25 fps slower than a 1:9″ twist).
Above, data shows relationship between Twist Rate and Muzzle Velocity (MV) for various barrel twist rates and rifling types. From fast to slow, the three 1:10″ twist barrels are: 5R (canted land), 5 Groove, 5 Groove left-hand twist.
We proceeded with testing all 6 barrels, with twist rates from 1:8″ to 1:12″. After all the smoke cleared, we found that muzzle velocity correlates to twist rate at the average rate of approximately 1.33 fps per inch of twist. In other words, your velocity is reduced by about 5 fps if you go from a 1:12″ twist to a 1:8″ twist. [Editor: That’s an average for all the lengths tested. The actual variance between 1:12″ and 1:8″ here was 8 FPS.] In this case the math prediction was pretty close, and we have to remember that there’s always uncertainty in the live fire results. Uncertainty is always considered in terms of what conclusions the results can actually support with confidence.
This is just a brief synopsis of a single test case. The coverage of twist rates in Modern Advancements in Long-Range Shooting Vol. 1 is more detailed, with multiple live fire tests. Results are extrapolated for other calibers and bullet weights. Needless to say, the question of “how twist rate affects muzzle velocity” is fully answered.
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 as an eBook in Amazon Kindle format.
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Christmas is 23 days away. If you are looking for a great gift for a shooting buddy, books have always been popular holiday gifts. Here are some recommended titles that should please the serious shooters and firearms enthusiasts on your shopping list. For shooting clubs, books also make great end-of-season member awards. Most of us would rather have a useful book than one more piece of wood to toss in a box in the closet. Check out these twelve titles — for yourself or your shooting buddies.
Here Are a DOZEN BOOKS Recommended for Serious Shooters:
If you’re a serious long-range shooter, consider adding this book to your library. Relying on extensive ballistics testing, Modern Advancements, Volume II is a great successor to Volume I that contains some fascinating research results. UK gun writer Laurie Holland notes: “Volume II of the Modern Advancements series is as fascinating as Volume I and if anything even more valuable given a series of ‘mythbusters’ tests including: case fill-ratio, primer flash-hole uniforming, neck tension, annealing, and much more. The work also addresses that perennial discussion of a bullet ‘going to sleep’ and shooting smaller groups (in MOA) at longer distances than 100 yards.” The amount of testing done for this Volume II work, with a staggering amount of rounds sent downrange, makes this book unique among shooting resources. There is a ton of “hard science” in this book — not just opinions.
Nancy Tompkins is one of the greatest long-range shooters in American history. She has won five National Long-range Championships. Tompkins’ treatise is a must-read for serious Palma, F-Class, and High Power shooters. The revised Second edition includes F-Class equipment and techniques, and newly updated information. Color pictures. Topics include Mental & Physical training, Reading Wind & Mirage Shooting Fundamentals, International Competition, and Loading for Long Range. Nancy Tompkins is a 4-time winner of the National Long Range Championships, and has won countless other major events. Nancy has been on six Palma Teams (as both a shooter and a coach).
The lastest edition of The Wind Book was released in 2020. The updates make this very helpful 144-page book even better. The Wind Book for Rifle Shooters by Linda Miller and Keith Cunningham, first published in 2007, is a very informative resource. But you don’t have to take our word for it. If you click this link, you can read book excerpts on Amazon.com. This lets you preview the first few chapters, and see some illustrations. Other books cover wind reading in a broader discussion of ballistics or long-range shooting. But the Miller & Cunningham book is ALL about wind reading from cover to cover, and that is its strength. The book focuses on real world skills that can help you accurately gauge wind angle, wind velocity, and wind cycles. Readers have praised the book, earning it 93% 4- and 5-star reviews on Amazon.
Ryan Cleckner is noted for his ability to explain complex topics in an easy-to-comprehend manner. Now Cleckner has authored a book, the Long Range Shooting Handbook, which expands on the topics covered in Cleckner’s popular NSSF video series. The Long Range Shooting Handbook is divided into three main categories: What It Is/How It Works, Fundamentals, and How to Use It. “What It Is/How It Works” covers equipment, terminology, and basic principles. “Fundamentals” covers the theory of long range shooting. “How to Use It” gives practical advice on implementing what you’ve learned, so you can progress as a skilled, long range shooter. You can view Sample Chapters from Ryan’s Book on Amazon.com.
Visualization is a process of mental preparation that is done before you get to the range. Many of the greatest shooting champions have used this technique to get ready for big matches, and to optimize their performance during record fire. If you want to enhance your “mental game” through pre-match visualization, we strongly recommend Lanny Bassham’s book, With Winning in Mind. As a competitive smallbore 3P shooter, Bassham developed a mental management system. Using this system, Lanny Bassham won 22 world individual and team titles, set four world records, and captured an Olympic Gold Medal in Montreal in 1976. His techniques have been embraced by professional and Olympic athletes in many sports. With Winning in Mind covers a complete system of “mental management” techniques used by Olympians and elite champions.
This book should be on the shelf of every short-range benchrest shooter. (Shooters in other disciplines will find the book helpful as well.) Butch Lambert says Mike’s book is “far and away the best Benchrest book written. Very comprehensive, it touches on every aspect of our game.” Mike’s 368-page book is dedicated to getting the most from modern rifle accuracy equipment with an emphasis on shooting 100-200-300 yard group benchrest tournaments. This book covers the most popular hardware plus new equipment offerings are covered, including external mount scopes, actions, triggers, stocks, wind flags, and more. Also covered are rifle handling techniques, note taking, tuning, bullet selection, goals, and match strategies. Mike provides many tips that will help active competitors update their own competitive program.
Thinking of getting started in the Practical/Tactical shooting game? Looking for ways to be more stable when shooting from unconventional positions? Then you may want to read Marcus Blanchard’s Practical Shooter’s Guide (A How-To Approach for Unconventional Firing Positions and Training). Unlike almost every “how to shoot” book on the market, Blanchard’s work focuses on the shooting skills and positions you need to succeed in PRS matches and similar tactical competitions. Blanchard provides clear advice on shooting from barricades, from roof-tops, from steep angles. Blanchard says you need to train for these types of challenges: “I believe the largest factor in the improvement of the average shooter isn’t necessarily the gear; it’s the way the shooter approaches obstacles and how they properly train for them.”
Tony Boyer, the most successful shooter in the history of short-range benchrest competition, shares match-winning tips in this 323-page book. The book covers all aspect of the benchrest discipline: loading, windflags, rest set-up, addressing the rifle, and match strategies. This is a high-quality publication, filled with valuable insights. Every serious benchrest shooter should read Tony’s book. Boyer has dominated registered benchrest in a fashion that will never be duplicated, having amassed 142 U.S. Benchrest Hall of Fame points. The next closest shooter, Allie Euber, has 47 Hall of Fame points. This handsome, full-color book is 323 pages long, with color photos or color illustrations on nearly every page.
This book by 11-time National High Power Champion David Tubb focuses on position shooting and High Power disciplines. Section One covers fundamentals: position points, natural point of aim, breathing, triggering mechanics and follow-through, sling selection and use, getting started, getting better, avoiding obstacles. Section Two covers mechanics of offhand, sitting, and prone positions. Section Three covers shooting skills, including wind reading and mental preparation. Section Four covers the technical side of shooting, with extensive discussions of rifle design, load development, reloading barrel maintenance, and rifle fitting. We consider this book a “must-read” for any sling shooter, and there is plenty of good advice for F-Class shooters too.
Another fine book for PRS/NRL shooting is Precision Rifle Marksmanship: The Fundamentals by Frank Galli, founder of SnipersHide.com. Former USMC scout-sniper Frank Galli explains techniques will benefit any PRS/NRL competitor. Along with position shooting tips, Galli offers great wind-reading advice. Published in 2020, Galli’s treatise is four years newer than Blanchard’s book, so it includes more of the latest gear and equipment. Galli’s book covers the fundamentals of precision marksmanship with easy-to-understand methodology. The book follows the same instruction process Galli uses in his live marksmanship classes. Published in 2020, this well-illustrated, 272-page book covers the latest equipment (scopes, LRFs, chassis systems, magazines, bags, bipods, tripods) favored by tactical competitors in PRS/NRL type matches.
Cartridges of the World (17th Edition, 2022), belongs in every serious gun guy’s library. This massive 704-page reference contains illustrations and basic load data for over 1500 cartridges. If you load for a wide variety of cartridges, or are a cartridge collector, this book is a “must-have” resource. The latest edition includes dozens of new cartridges and boasts 1500+ photos. The 17th Edition of Cartridges of the World includes cartridge specs, plus tech articles on Cartridge identification, SAAMI guidelines, wildcatting, and new cartridge design trends. In scope and level of detail, Cartridges of the World is the most complete cartridge reference guide in print. Cartridges of the World now includes a full-color section with feature articles.
Gary Anderson’s book, Coaching Young Rifle Shooters, is an excellent, fully-illustrated guide for training young shooters. This 187-page, full-color book is the most comprehensive instructional guide of its kind now in print. Anderson created this resource for coaches and parents who work with beginning and intermediate junior rifle shooters. Anderson’s guidebook provides coaches with the tools needed to develop young shooters and improve their marksmanship skills. Gary Anderson is the Director of Civilian Marksmanship (DCM) Emeritus. In his 11 years of international competition, Gary won two Olympic gold medals, seven World Championships, and 16 national titles.
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A number of interesting jobs in the firearms industry have become available in recent weeks. The NSSF maintains a regularly-updated listing of employment opportunities with gun-makers and shooting sports organizations. On the NSSF Career Center right now there are executive openings, engineering jobs, tech placements, account manager positions, sales and marketing positions, and digital media opportunities. Here are some of the jobs we found this week posted on the NSSF Website. CLICK HERE to visit the NSSF Career Center with all current listings.
Firearms Industry Jobs — Current Openings
The gun industry needs skilled personnel! The total number of full-time equivalent jobs in the firearms industry rose from approximately 166,000 in 2008 to almost 342,330 in 2020, a 106% increase. Here are some current job openings posted on the NSSF Career Center:
Want to improve your understanding of Ballistics, Bullet Design, Bullet Pointing, and other shooting-related tech topics? Well here’s a treasure trove of gun expertise. Applied Ballistics offers dozens of FREE tech articles on its website. Curious about Coriolis? — You’ll find answers. Want to understand the difference between G1 and G7 BC? — There’s an article about that.
“Doc” Beech, technical support specialist at Applied Ballistics says these articles can help shooters working with ballistics programs: “One of the biggest issues I have seen is the misunderstanding… about a bullet’s ballistic coefficient (BC) and what it really means. Several papers on ballistic coefficient are available for shooters to review on the website.”
Credit Shooting Sports USA Editor John Parker for finding this great resource. John writes: “Our friends at Applied Ballistics have a real gold mine of articles on the science of accurate shooting on their website. This is a fantastic source for precision shooting information[.] Topics presented are wide-ranging — from ballistic coefficients to bullet analysis.”
Here are six (6) of our favorite Applied Ballistics articles, available for FREE to read online. There are dozens more, all available on the Applied Ballistics Education Webpage. After Clicking link, select Plus (+) Symbol for “White Papers”, then find the article(s) you want in the list. For each selection, then click “Download” in the right column. This will send a PDF version to your device.
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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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The Modern Advancements series is an ongoing journal of the R&D activities at Applied Ballistics. Theories of ballistics are explored “myth-buster” style with extensive live fire testing. Employing state-of-the-art ballistic instrumentation including Doppler Radar and high-speed (Phantom) video, the Applied Ballistics team has made key insights about ballistics which are then shared through books and the Science of Accuracy Academy.
This 3rd Volume of the series has 13 Chapters. The book features four main parts: Part 1: Precision Testing, Part 2: Advanced Handloading, Part 3: Doppler Radar Testing, and Part 4: Miscellaneous.
Pre-orders for individuals and dealers opened July 26, 2022, and end when the books ship in late August or early September. During the pre-order phase, subscribers of The Science of Accuracy Academy will get a $20 off coupon for the new book. Other ballistics books by Bryan Litz are available through the Science of Accuracy Academy STORE.
About Applied Ballistics
Applied Ballistics’ mission is to be a complete, unbiased source of external ballistics information for long-range shooters. We’re highly active in R&D, constantly testing new claims, products, and ideas for potential merit and dispensing with the marketing hype which can make it so difficult for shooters to master the challenging discipline of long-range shooting.
We believe in the scientific method and promote mastery through an understanding of the fundamentals. Our work serves the shooting community via instructional materials which are easy to understand, and products such as ballistic software which runs on many platforms. If you’re a long-range shooter who’s eager to learn about the science of your craft, we’re here for you.
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Many barrel-makers mark the twist rate and bore dimensions on their barrel blanks.
Does muzzle velocity change with faster or slower barrel twist rates? Absolutely, but much less than you might think. Faster twist rates do slow down bullets somewhat, but the speed loss is NOT that significant. With Bartlein .308 Win barrels of identical length and contour, a 1:12″-twist barrel was only 8 fps faster than a 1:8″-twist barrel. That was the result of testing by Applied Ballistics.
The Applied Ballistics team tested six (6) same-length/same-contour Bartlein barrels to observe how twist rate might affect muzzle velocity. This unique, multi-barrel test is featured in the book Modern Advancements in Long Range Shooting, Vol. 1. That book includes other fascinating field tests, including a comprehensive chronograph comparison.
Barrel Twist Rate vs. Velocity — What Tests Reveal by Bryan Litz
When considering barrel twist rates, it’s a common belief that faster twist rates will reduce muzzle velocity. The thinking is that the faster twist rate will resist forward motion of the bullet and slow it down. There are anecdotal accounts of this, such as when someone replaces a barrel of one brand/twist with a different brand and twist and observes a different muzzle velocity. But how do you know the twist rate is what affected muzzle velocity and not the barrel finish, or bore/groove dimensions? Did you use the same chronograph to measure velocity from both barrels? Do you really trust your chronograph?
Summary of Test Results
After all the smoke cleared, we found that muzzle velocity correlates to twist rate at the average rate of approximately 1.33 FPS per inch of twist. In other words, your velocity is reduced by about 5 FPS if you go from a 1:12″ twist to a 1:8″ twist. — Bryan Litz
Savage Test Rifle with Six Bartlein Barrels
Most shooters don’t have access to the equipment required to fully explore questions like this. These are exactly the kinds of things we examine in the book Modern Advancements in Long Range Shooting, Vol. 1. In that book, we present experiments conducted in the Applied Ballistics lab. Some of those experiments took on a “Myth Buster” tone as we sought to confirm (or deny) popular pre-conceptions. For example, here’s how we approached the question of barrel twist and muzzle velocity.
Six .308 Win Barrels from Bartlein — All Shot from the Same Rifle
We acquired six (6) barrels from the same manufacturer (Bartlein), all the same length and contour, and all chambered with the same reamer (SAAMI spec .308 Winchester). All these barrels were fitted to the same Savage Precision Target action, and fired from the same stock, and bench set-up. Common ammo was fired from all six barrels having different twist rates and rifling configurations. In this way, we’re truly able to compare what effect the actual twist rate has on muzzle velocity with a reasonable degree of confidence.
Prior to live fire testing, we explored the theoretical basis of the project, doing the physics. In this case, an energy balance is presented which predicts how much velocity you should expect to lose for a bullet that’s got a little more rotational energy from the faster twist. In the case of the .30 caliber 175 grain bullets, the math predicts a loss of 1.25 fps per inch-unit of barrel twist (e.g. a 1:8″ twist is predicted to be 1.25 fps slower than a 1:9″ twist).
Above, data shows relationship between Twist Rate and Muzzle Velocity (MV) for various barrel twist rates and rifling types. From fast to slow, the three 1:10″ twist barrels are: 5R (canted land), 5 Groove, 5 Groove left-hand twist.
We proceeded with testing all 6 barrels, with twist rates from 1:8″ to 1:12″. After all the smoke cleared, we found that muzzle velocity correlates to twist rate at the average rate of approximately 1.33 fps per inch of twist. In other words, your velocity is reduced by about 5 fps if you go from a 1:12″ twist to a 1:8″ twist. [Editor: That’s an average for all the lengths tested. The actual variance between 1:12″ and 1:8″ here was 8 FPS.] In this case the math prediction was pretty close, and we have to remember that there’s always uncertainty in the live fire results. Uncertainty is always considered in terms of what conclusions the results can actually support with confidence.
This is just a brief synopsis of a single test case. The coverage of twist rates in Modern Advancements in Long-Range Shooting Vol. 1 is more detailed, with multiple live fire tests. Results are extrapolated for other calibers and bullet weights. Needless to say, the question of “how twist rate affects muzzle velocity” is fully answered.
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 as an eBook in Amazon Kindle format.
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CLICK HERE to see full-screen version of Wind Plot.
Team shooting is very different than individual competition. Typically a team coach makes the wind calls for the shooters. In some cases (where the rules allow), the wind coach even dials elevation and windage changes for the active shooter. For the wind coach to do his job effectively, he must follow the changes in the wind and determine what the correct wind call should have been for each shot. (In other words — what was the “right call”)
Bryan Litz, founder of Applied Ballistics and Past USA F-TR National Champion, served as wind coach for the winning 4-man F-TR Team at the 2017 Canadian F-Class Championships, which preceded the F-Class World Championships also held in Canada. Here Bryan explains how he has used a Wind Plot to make better wind calls, helping his team-mates maximize their scores.
Wind Plot Methodology by Bryan Litz
The wind plot I use is a running history of what the correct wind call was for every shot fired. The more you shoot, the more history you have in a condition, and I find that very useful information. This kind of plot IS NOT showing where the bullet hit, and is NOT showing what you held. It’s showing what you should have held to center each shot. IMO, this is the most valuable information to have when guessing where to hold next for each shot. Here are some key points:
1. I always look for blocks of stable conditions to shoot in and wait out the rest.
2. If the wind plot shows drastic changes, either I’m not picking the right time to shoot or it’s just a really unstable wind condition.
3. When you see many shots using the same hold (e.g. Robby’s 700m and 900m strings on plot), it can indicate very fast shooting and fast pit service.
Q. What are the numbers and Markings on this Wind Plot?
Litz: The wind plot represents the rings on the target. Left 2 for example, is the 5 line on the international target, while Left 2 is the 10 line on the USA target. F-Class shooters and coaches talk about wind holds in relation to these rings. A Left 2 hold isn’t left 2 MOA or 2 MILS, it’s the second ring from center. The vertical lines on the plot represent the rings going out from center, 4 or 5 in each direction. A left or right 5 hold is edge of black on the int’l target.
Q: What Does this Specific Plot Reveal?
Litz: Looking at the plot, from left to right is 700m, 800m, and 900m that we shot progressively through the day. Top to bottom shows each shooter in sequence (shooters names are shown by their blocks). To the right I note what was on the gun for that shooter, and note when it changes. Often times we run the same wind on the gun for several shooters but if it changes, I note what the new windage is and continue on. For example if we’re settled into a condition where we’re shooting Vs with a right 3 hold, I might adjust the scope 1 MOA right because a right 3 hold is equal to 1 MOA. So we can move the scope and start shooting with a center hold.
Q. Are you Plotting Where the Bullet Hits?
Litz: Not exactly. This kind of plot IS NOT specifically showing where the bullet hit, and IS NOT showing what the shooter held. It’s showing what the shooter should have held to center each shot. IMO, this is the most valuable information to have when guessing where to hold next for each shot.
On each shot, the shooter or coach takes a guess about where to hold, and fires the shot. If the bullet hits the center, you plot the point right where you held because it was the correct hold. However, if you miss the call, you plot what hold was required to put that shot in the center. For example if you shoot a right 3 and hit where you held, the correct call would have been “center”. In this way, you’re building a history of what you should have done, which may or may not be what you actually did. This shows you the trends, and brackets which can be used to make future decisions.
Q: Is this Type of Wind Plot Something New?
Litz: I didn’t invent this method, it’s been around a long time. Vertical can be plotted the same way. In team matches, we have a plotter who is advising on elevation trends and suggesting corrections. But, as wind coach, my job is the horizontal so I only keep the wind plot. I have learned lots of strategies from my coaches Emil Praslick and Steve Hardin.
There are many ways to plot and many standard work sheets for this. They’re all tools and the key is to find something that works for you in different situations. I don’t keep a plot when I am personally behind the trigger string firing because I lose more points when I take the time to do it vs. just shooting fast. When pair firing or coaching, I can keep the wind plot without compromising the shooting.
Here Team Australia used plots and communication gear linking coaches. This helped the Aussies win the 2013 F-Open Team World Championship held at Raton, NM.
Know Your Goal — Keep It Simple
Know your goal of plotting. The simplest plot is where you write the shot number where it hit on a target face. This kind of plotting is useful for evaluating shooter performance because it shows how big the group is (in particular the vertical dispersion). However keeping a plot like this does little to help you figure out the wind. It just shows you what shots you messed up on. It does nothing to help you find the center. [Editor: That’s a whole different matter with many variables.] The wind plot I use is a running history of what the correct wind call was for every shot fired. The more you shoot, the more history you have in a condition, and I find that very useful information.
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Q: What’s more important — wind speed, or direction?
A: Obviously they both matter, but they do trade dominance based on direction. For example, a 10 mph wind between 2:30 and 3:30 is only changing its value from 9.7 to 10 to 9.7 mph (bracket of 0.3 mph). However a 10 mph wind between 11:30 and 12:30 is changing its cross wind component value from 2.6 mph left to zero to 2.6 mph right (bracket of 5.2 mph). There is the same 30° change in direction, but this results in a massively different bracket.
Point being, in this case, a direction change is far more critical if it’s near 6 or 12 o’clock. A small direction change when it’s close to 3 or 9 o’clock is negligible.
On the contrary, a change in wind SPEED when it’s near 3 or 9 affects your crosswind component directly. But for a near head or tail wind, a fluctuation in wind speed only causes a small fraction of a change to the crosswind component.
SUMMARY: If you’re in a near full-value wind, pay more attention to wind SPEED. If you’re closer to a head- or tail-wind, nailing the exact DIRECTION will be more important.
Get More Tips on Bryan Litz Ballistics Facebook Page
This post is from the new Bryan Litz Ballistics Facebook Page. FB users should check that page regularly for more tips from Bryan, American’s leading ballistics expert and founder of Applied Ballistics LLC.
Bryan Litz coaching Team USA in Canada using a WIND PLOT.
BIG NEWS Coming Soon: Bryan Litz and Applied Ballistics will make a Major Announcement tonight, April 19, 2022. The Announcement will be featured on Facebook and other Social Media, and we’ll have a report in tomorrow’s Daily Bulletin.
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Want to learn more about Long Range Shooting? Check out the NSFF “Elements of Long Range Shooting” videos hosted by ballistics guru Bryan Litz of Applied Ballistics. In this multi-part series, Bryan covers a variety of topics of interest to precision shooters. For today’s Saturday at the Movies special, we feature seven of Bryan’s videos. Watch other informative Long Range Shooting and Ballistics videos with Bryan Litz on the NSSF YouTube Channel.
Atmospherics and Density Altitude
Bryan Litz explains: “An important element in calculating an accurate firing solution for long-range shooting is understanding the effects of atmospherics on a projectile.” Atmospherics include air pressure, air temperature, and humidity. Bryan notes: “Temperature, pressure, and humidity all affect the air density… that the bullet is flying through. You can combine all those factors into one variable called ‘Density Altitude’.” Density Altitude is used by the ballistic solver to account for variables that affect bullet flight.
Bullet Ballistic Coefficients
A bullet’s ballistic coefficient (BC) basically expresses how well the bullet flies through the air. Higher BC bullets have less aerodynamic drag than lower BC projectiles. You will see BCs listed as either G1 and G7 numbers. These correspond to different bullet shape models. Generally speaking, the G7 model works better for the long, boat-tail bullets used for long-range shooting. Notably, a bullet’s drag is NOT constant in flight. The true BC can vary over the course of the trajectory as the bullet velocity degrades. In other words, “BC is dynamic”. That said, you can make very accurate drop charts using the BCs provided by major bullet-makers, as plugged into solvers. However, long-range competitors may want to record “real world” drop numbers at various distances. For example, we’ve seen trajectories be higher than predicted at 500 yards, yet lower than predicted at 1000.
Transonic Range
When considering your rifle’s long-range performance, you need to understand the limit of your bullet’s supersonic range. As the bullet slows below the speed of sound, it enters the transonic zone. This can be accompanied by variations in stability as well as BC changes. Bryan explains “once your bullet slows done below supersonic and you get into transonic effects, there are a lot more considerations that come into play. The drag of the bullet becomes less certain, the stability of the bullet can be challenged, and things related to long times of flight, such as Coriolis and Spin Drift, come into play. So whenever you are shooting long range you need to where your bullet slows down to about 1340 fps.”
Ballistics Solvers — Many Options
Bryan Litz observes: “When we talk about the elements of long range shooting, obviously a very important element is a getting a fire solution, using a ballistic solver. There are a lot of ballistic solvers out there… Applied Ballistics has smartphone Apps. Applied Ballistics has integrated the ballistic solver directly into a Kestral, and the same solver runs (manually) on the Accuracy Solutions Wiz-Wheel. The point is, if it is an Applied Ballistics device it is running the same solutions across the board.”
Bullet Stability and Twist Rates
In this video, Bryan Litz talks about bullet in-flight stability and how to calculate barrel twist-rate requirements for long-range bullets. Bryan explains that bullet stability (for conventional projectiles) is basically provided by the spinning of the bullet. But this spin rate is a function of BOTH the nominal twist rate of the barrel AND the velocity of the projectile. Thus, when shooting the same bullet, a very high-speed cartridge may work with a slower barrel twist rate than is required for a lower-speed (less powerful) cartridge. For match bullets, shot at ranges to 1000 yards and beyond, Bryan recommends a twist rate that offers good stability.
Scope Tracking — Tall Target Test
Have you recently purchased a new scope? Then you should verify the actual click value of the turrets before you use the optic in competition. While a scope may have listed click values of 1/4-MOA, 1/8-MOA or 0.1 Mils, the reality may be slightly different. Many scopes have actual click values that are slightly higher or lower than the value claimed by the manufacturer. The small variance adds up when you click through a wide range of elevation. In this video, Bryan Litz shows how to verify your true click values using a “Tall Target Test”. The idea is to start at the bottom end of a vertical line, and then click up 30 MOA or so. Multiply the number of clicked MOA by 1.047 to get the claimed value in inches. For example, at 100 yards, 30 MOA is exactly 31.41 inches. Then measure the difference in your actual point of impact.
Coriolis Effect
The Coriolis Effect comes into play with extreme long-range shots. The rotation of the earth actually moves the target a small distance (in space) during the long duration of the bullet’s flight. Bryan Litz notes that, in most common shooting situations inside 1K, Coriolis is not significant. At 1000 yards, the Effect represents less than one click (for most cartridge types). Even well past 1000 yards, in windy conditions, the Coriolis Effect may well be “lost in the noise”. But in very calm conditions, when shooting at extreme ranges, Bryan says you can benefit from adjusting your ballistics solution for Coriolis: “The Coriolis Effect… has to do with the spin of the earth. The consequence of that is that, if the flight time of the bullet gets significantly long, the bullet can have an apparent drift from its intended target. The amount [of apparent drift] is very small — it depends on your latitude and azimuth of fire on the planet.”
About Bryan Litz
Bryan began his career as a rocket scientist, quite literally. He then started Applied Ballistics, the leading company focusing on ballistics science for rifle shooting. A past F-TR Long-Range National Champion and Chief Ballistician for Berger Bullets, knows his stuff. His Applied Ballistics squad was the winning team at the 2017 King of 2 Miles event, and Applied Ballistics has earned major U.S. defense contracts.
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Here’s a smart tip from Bryan Litz, explaining how damage to a bullet jacket can harm the projectile’s Ballistic Coefficient (BC). This tip is posted on Bryan’s new Bryan Litz Ballistics Facebook page. We recommend you subscribe to that page to access Bryan’s latest informative posts.
Bryan notes: “If the case mouth scratches the bullet when you seat it, the damage can cause the BC to be inconsistent, which shows up as vertical dispersion at long range.
We see this sometimes when running Doppler Radar for competitors at Applied Ballistics Mobile Lab events. If someone is shooting a bullet that typically has a very consistent BC (1% or less) but they’re seeing a higher BC variation, it can be due to the bullets being damaged in the loading process.”
The lead photo above shows the badly-scratched jacket of a bullet seated in a rough-mouthed case. To prevent such jacket damage, one should chamfer, deburr, and smooth case mouths after trimming.
Below is a recorded Doppler radar result showing excessive BC variation. Such variation can increase vertical disperson at long range. This can result in larger group sizes and lower scores.
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Colby Hodnett works as a long-range instructor with Accuracy 1st. In addition to being an avid hunter, angler, and outdoor enthusiast, Colby is a Commercial helicopter pilot, certified flight instructor, NRA-certified pistol instructor, and aircraft mechanic. Colby, along with his father Todd, continue to serve the Kestrel community by being a resource for all-things long-range shooting.
A number of interesting jobs in the firearms industry have become available in recent weeks. The NSSF maintains a regularly-updated listing of employment opportunities with gun-makers and shooting sports organizations. On the 
Hybrid Bullet Design — Best of Both Worlds?
