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March 7th, 2023

MIL vs. MOA — Angular Measurements for Optics Explained

Mil MOA reticle ranging PRS tactical minute angle precision rifle series
Visit PrecisionRifleBlog.com for a discussion of MIL vs. MOA.

Many guys getting started in long range shooting are confused about what kind of scope they should buy — specifically whether it should have MIL-based clicks or MOA-based clicks. Before you can make that decision, you need to understand the terminology. This article, with a video by Bryan Litz, explains MILS and MOA so you can choose the right type of scope for your intended application.

This March-FX 5-40x56mm Tactical FFP scope features 0.05 MIL Clicks.
Mil MOA reticle ranging PRS tactical minute angle precision rifle series

You probably know that MOA stands for “Minute of Angle” (or more precisely “minute of arc”), but could you define the terms “Milrad” or “MIL”? In a helpful video, Bryan Litz of Applied Ballitics explains MOA and MILs (short for “milliradians”). Bryan defines those terms and explains how they are used. One MOA is an angular measurement (1/60th of one degree) that subtends 1.047″ at 100 yards. One MIL (i.e. one milliradian) subtends 1/10th meter at 100 meters; that means that 0.1 Mil is one centimeter (1 cm) at 100 meters. Is one angular measurement system better than another? Not necessarily… Bryan explains that Mildot scopes may be handy for ranging, but scopes with MOA-based clicks work just fine for precision work at known distances. Also because one MOA is almost exactly one inch at 100 yards, the MOA system is convenient for expressing a rifle’s accuracy. By common parlance, a “half-MOA” rifle can shoot groups that are 1/2-inch (or smaller) at 100 yards.

What is a “Minute” of Angle?
When talking about angular degrees, a “minute” is simply 1/60th. So a “Minute of Angle” is simply 1/60th of one degree of a central angle, measured either up and down (for elevation) or side to side (for windage). At 100 yards, 1 MOA equals 1.047″ on the target. This is often rounded to one inch for simplicity. Say, for example, you click up 1 MOA (four clicks on a 1/4-MOA scope). That is roughly 1 inch at 100 yards, or roughly 4 inches at 400 yards, since the target area measured by an MOA subtension increases with the distance.

one MOA minute of angle diagram

MIL vs. MOA for Target Ranging
MIL or MOA — which angular measuring system is better for target ranging (and hold-offs)? In a recent article on his PrecisionRifleBlog.com website, Cal Zant tackles that question. Analyzing the pros and cons of each, Zant concludes that both systems work well, provided you have compatible click values on your scope. Zant does note that a 1/4 MOA division is “slightly more precise” than 1/10th mil, but that’s really not a big deal: “Technically, 1/4 MOA clicks provide a little finer adjustments than 1/10 MIL. This difference is very slight… it only equates to 0.1″ difference in adjustments at 100 yards or 1″ at 1,000 yards[.]” Zant adds that, in practical terms, both 1/4-MOA clicks and 1/10th-MIL clicks work well in the field: “Most shooters agree that 1/4 MOA or 1/10 MIL are both right around that sweet spot.”

READ MIL vs. MOA Cal Zant Article.

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February 18th, 2023

Scratches on Bullet Jackets Affect BC and Long Range Accuracy

applied ballistics mobile lab schedule

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.

applied ballistics mobile lab schedule

applied ballistics mobile lab schedule

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February 5th, 2023

G1 vs. G7 Ballistic Coefficients — What You Need to Know

G1 G7 BC drag models

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.

G1 G7 Ballistic coefficients

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.

G7 BCs:
Berger 180 VLD: 0.337 lb/in²
JLK 180: 0.330 lb/in²

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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January 31st, 2023

Shooting on a Spinning Planet — Explaining the Coriolis Effect

Whittington Coriolis Effect
Photo by Dustin Ellermann at Whittington Center Range.

The Coriolis Effect comes into play with extreme long-range shots like this (2100 yards at Raton, New Mexico). The rotation of the earth actually moves the target a small distance (in space) during the long duration of the bullet’s flight.

Coriolis Effect Bryan Litz Applied BallisticsWhen you’re out at the range, the Earth seems very stable. But it is actually a big sphere zooming through space while spinning around its axis, one complete turn every 24 hours. The rotation of the earth can create problems for extreme long-range shooters. During extended bullet flight times, the rotation of the planet causes an apparent deflection of the bullet path over very long distances. This is the ballistics manifestation of the Coriolis Effect.

Bryan Litz of Applied Ballistics discusses explains the Coriolis Effect in his Ballistics Books and Seminars. Bryan notes that Coriolis is “a very subtle effect. People like to make more of it than it is because it seems mysterious.” In most common shooting situations inside 1K, Coriolis is not important. 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.

Bryan explains: “The Coriolis Effect… has to do with the spin of the earth. You are basically shooting from one point to another on a rotating sphere, in an inertial reference frame. 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.”

Coriolis Effect Bryan Litz Applied Ballistics

Coriolis is a very subtle effect. With typical bullet BCs and velocities, you must get to at least 1000 yards before Coriolis amounts to even one click. Accordingly, Bryan advises: “Coriolis Effect is NOT something to think about on moving targets, it is NOT something to think about in high, uncertain wind environments because there are variables that are dominating your uncertainty picture, and the Coriolis will distract you more than the correction is worth.”

“Where you could think about Coriolis, and have it be a major impact on your hit percentage, is if you are shooting at extended range, at relatively small targets, in low-wind conditions. Where you know your muzzle velocity and BC very well, [and there are] pristine conditions, that’s where you’re going to see Coriolis creep in. You’ll receive more refinement and accuracy in your ballistics solutions if you account for Coriolis on those types of shots. But in most practical long-range shooting situations, Coriolis is NOT important. What IS important is to understand is when you should think about it and when you shouldn’t, i.e. when applying it will matter and when it won’t.”

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January 19th, 2023

Panel of Ballistics Experts at Kestrel SHOT Show Booth Today

Bryan Litz Applied Ballistics SHOT Show Kestrel booth 2023

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.

Bryan Litz Applied Ballistics SHOT Show Kestrel booth 2023

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.

applied ballistics mitchell fitzpatrick
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.

Bryan Litz Applied Ballistics SHOT Show Kestrel booth 2023Colby 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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January 13th, 2023

On Friday the 13th — How to Avoid Train Wrecks at Matches

train wreck Bryan Litz shooting tips ballistics friday 13 13th

Today is Friday the 13th. For those of you who are superstitious — maybe you should avoid climbing ladders, playing the stock market, or using power tools today.

When it comes to shooting, there are many things that shooters chalk up to “bad luck”. In fact, most of these instances of “bad fortune” just come from a failure to anticipate problems. When you have a major, critical problem at a shooting match, i.e. a “train wreck”, this can be the end of your weekend. In this article, Ballistics Guru Bryan Litz talks about “train wrecks” and how to avoid them, even if you are shooting on Friday the 13th. As Bryan told us: “I don’t believe in superstition — we make our own luck!”

How to Avoid “Train Wrecks” In Competition

In any shooting competition, you must try to avoid major screw-ups that can ruin your day (or your match). In this article, past F-TR National Mid-Range and Long Range Champion Bryan Litz talks about “Train Wrecks”, i.e. those big disasters (such as equipment failures) that can ruin a whole match. Bryan illustrates the types of “train wrecks” that commonly befall competitors, and he explains how to avoid these “unmitigated disasters”.

Urban Dictionary “Train Wreck” Definition: “A total @#$&! disaster … the kind that makes you want to shake your head.”

train wreck Bryan Litz shooting tips ballisticsTrain Wrecks (and How to Avoid Them)
by Bryan Litz of Applied Ballistics LLC.

Success in long range competition depends on many things. Those who aspire to be competitive are usually detail-oriented, and focused on all the small things that might give them an edge. Unfortunately it’s common for shooters lose sight of the big picture — missing the forest for the trees, so to speak.

Consistency is one of the universal principles of successful shooting. The tournament champion is the shooter with the highest average performance over several days, often times not winning a single match. While you can win tournaments without an isolated stellar performance, you cannot win tournaments if you have a single train wreck performance. And this is why it’s important for the detail-oriented shooter to keep an eye out for potential “big picture” problems that can derail the train of success!

Train wrecks can be defined differently by shooters of various skill levels and categories. Anything from problems causing a miss, to problems causing a 3/4-MOA shift in wind zero can manifest as a train wreck, depending on the kind of shooting you’re doing.

Below is a list of common Shooting Match Train Wrecks, and suggestions for avoiding them.

1. Cross-Firing. The fastest and most common way to destroy your score (and any hopes of winning a tournament) is to cross-fire. The cure is obviously basic awareness of your target number on each shot, but you can stack the odds in your favor if you’re smart. For sling shooters, establish your Natural Point of Aim (NPA) and monitor that it doesn’t shift during your course of fire. If you’re doing this right, you’ll always come back on your target naturally, without deliberately checking each time. You should be doing this anyway, but avoiding cross-fires is another incentive for monitoring this important fundamental. In F-Class shooting, pay attention to how the rifle recoils, and where the crosshairs settle. If the crosshairs always settle to the right, either make an adjustment to your bipod, hold, or simply make sure to move back each shot. Also consider your scope. Running super high magnification can leave the number board out of the scope’s field view. That can really increase the risk of cross-firing.

2. Equipment Failure. There are a wide variety of equipment failures you may encounter at a match, from loose sight fasteners, to broken bipods, to high-round-count barrels that that suddenly “go south” (just to mention a few possibilities). Mechanical components can and do fail. The best policy is to put some thought into what the critical failure points are, monitor wear of these parts, and have spares ready. This is where an ounce of prevention can prevent a ton of train wreck. On this note, if you like running hot loads, consider whether that extra 20 fps is worth blowing up a bullet (10 points), sticking a bolt (DNF), or worse yet, causing injury to yourself or someone nearby.

train wreck Bryan Litz shooting tips ballistics

[Editor’s Note: The 2016 F-Class Nationals will employ electronic targets so conventional pit duties won’t be required. However, the following advice does apply for matches with conventional targets.]

3. Scoring/Pit Malfunction. Although not related to your shooting technique, doing things to insure you get at least fair treatment from your scorer and pit puller is a good idea. Try to meet the others on your target so they can associate a face with the shooter for whom they’re pulling. If you learn your scorer is a Democrat, it’s probably best not to tell Obama jokes before you go for record. If your pit puller is elderly, it may be unwise to shoot very rapidly and risk a shot being missed (by the pit worker), or having to call for a mark. Slowing down a second or two between shots might prevent a 5-minute delay and possibly an undeserved miss.

train wreck Bryan Litz shooting tips ballistics4. Wind Issues. Tricky winds derail many trains. A lot can be written about wind strategies, but here’s a simple tip about how to take the edge off a worse case scenario. You don’t have to start blazing away on the command of “Commence fire”. If the wind is blowing like a bastard when your time starts, just wait! You’re allotted 30 minutes to fire your string in long range slow fire. With average pit service, it might take you 10 minutes if you hustle, less in F-Class. Point being, you have about three times longer than you need. So let everyone else shoot through the storm and look for a window (or windows) of time which are not so adverse. Of course this is a risk, conditions might get worse if you wait. This is where judgment comes in. Just know you have options for managing time and keep an eye on the clock. Saving rounds in a slow fire match is a costly and embarrassing train wreck.

5. Mind Your Physical Health. While traveling for shooting matches, most shooters break their normal patterns of diet, sleep, alcohol consumption, etc. These disruptions to the norm can have detrimental effects on your body and your ability to shoot and even think clearly. If you’re used to an indoor job and eating salads in air-conditioned break rooms and you travel to a week-long rifle match which keeps you on your feet all day in 90-degree heat and high humidity, while eating greasy restaurant food, drinking beer and getting little sleep, then you might as well plan on daily train wrecks. If the match is four hours away, rather than leaving at 3:00 am and drinking five cups of coffee on the morning drive, arrive the night before and get a good night’s sleep.”

Keep focused on the important stuff. You never want to lose sight of the big picture. Keep the important, common sense things in mind as well as the minutia of meplat trimming, weighing powder to the kernel, and cleaning your barrel ’til it’s squeaky clean. Remember, all the little enhancements can’t make up for one big train wreck!

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December 29th, 2022

Wind Reading Wisdom from Bryan Litz and Emil Praslick III

Wind reading coaching bryan litz Ben Avery Phoenix wind video

Wind effects are complex. In trying to access wind speeds and angles, you’ll want to watch multiple indicators — mirage, dust, wind-flags, grass movement, and more. You’ll also need to be concerned about wind cycles. In the video below, Bryan Litz talks about variable wind speed along a bullet’s flight path. A respected ballistics guru, Bryan is the founder of Applied Ballistics and a designer of Berger’s Hybrid Match projectiles. He is also a past F-TR National Champion and a High Master Palma ace.

In this video, Bryan discusses how wind effects can vary in intensity at different points along the bullet’s flight path to the target. Sometimes the firing line is sheltered, and the strongest winds come into effect in the middle of the trajectory. Bryan concludes: “Wind matters everywhere … but the best thing you can do is try to get a handle on the wind [velocity and angle] where you are. That may or may not represent the wind down-range — that’s when you have to look downrange and make a judgment[.]”

Litz Competition Tip: Select your wind shooting strategy carefully. For beginners and veterans, most points are typically lost to wind. Successful shooters put a lot of thought into their approach to wind shooting. Sometimes it’s best to shoot fast and minimize the changes you’ll have to navigate. Other times it’s best to wait out a condition which may take several minutes. Develop a comfortable rest position so you have an easier time waiting when you should be waiting.

More Wind Tips from Wind Wizard Emil Praslick
In these two short videos, Emil Praslick III, former coach of the USAMU and USA National long range teams, explains how to find the wind direction and how to confirm your no-wind zero. Praslick is widely considered to be one of the best wind coaches in the USA.

When Winds Are EXTREME — Near Gale Force at Ben Avery

This video shows INSANE winds at NBRSA 100/200 Benchrest Nationals. This was filmed at the Ben Avery Range in Phoenix, AZ during the recent NBRSA 100/200 yard National Championships. Extreme to say the least. Based on what we’re seeing here, there are 20-25 mph crosswinds, with gusts to 35 mph — near Gale Force. Video by Hall-of-Fame Benchrest competitor Gene Bukys, whom we sadly lost to COVID last year. RIP Gene.

Texas gunsmith Mike Bryant reports: “This video shows the Unlimited Class 200 at the Nationals in Phoenix. I had three 10-shot groups in the low 2″ range with a 2.228″ being my big group and was glad they weren’t bigger. Thursday and Friday were the worst of the windy days. Unfortunately those were the days for the UL 200 and it was about as windy through most all of the Sporter 200.”

Excellent Wind Reading Resource

The Wind Book for Rifle Shooters covers techniques and tactics used by expert wind-readers. The authors provide a wind-reading “toolbox” for calculating wind speed, direction, deflection and drift. They explain how to read flags and mirage, record and interpret your observations, and time your shots to compensate for wind. Here are two reviews:

This is a must-have book if you are a long-range sport shooter. I compete in F-Class Open and when read it from cover to cover, it helped me understand wind reading and making accurate scope corrections. Buy this book, read it, put into practice what it tells you, you will not be disappointed. — P. Janzso

If you have one book for wind reading, this should be it. It covers how to get wind speed/direction from flags, mirage, and natural phenomenon. This is the best book for learning to read wind speed and direction. — Muddler

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December 28th, 2022

Barrel Twist Rate and Bullet Stability — What You Need to Know

FirearmsID.com barrel rifling diagram

Understanding Twist: Bullet Stabilization

by Sierra Bullets Ballistic Technician Paul Box for Sierra Bullets Blog.

Based on the questions we get on a daily basis on our 800 (Customer Support) line, twist is one of the most misunderstood subjects in the gun field. So let’s look deeper into this mystery and get a better understanding of what twist really means.

When you see the term 1:14″ (1-14) or 1:9″ twist, just exactly what does this mean? A rifle having a 1:14″ twist means the bullet will rotate one complete revolution every fourteen inches of the barrel. Naturally a 1:9″ turns one time every nine inches that it travels down the barrel. Now, here’s something that some people have trouble with. I’ve had calls from shooters thinking that a 1:14″ twist was faster than a 1:9″ because the number was higher with the 1:14″. The easiest way to remember this is the higher the number, the slower the twist rate is.

Now, the biggest misconception is that if a shooter has a .223 with a 1:8″ twist, his rifle won’t stabilize a 55gr bullet or anything lighter. So let’s look at what is required. The longer a bullet is for its diameter, the faster the twist has to be to stabilize it. In the case of the .223 with a 1:8″ twist, this was designed to stabilize 80gr bullets in this diameter. In truth the opposite is true. A 1:8″ will spin a 55gr faster than what is required in order to stabilize that length of bullet. If you have a bullet with good concentricity in its jacket, over-spinning it will not [normally] hurt its accuracy potential. [Editor’s Note: In addition, the faster twist rate will not, normally, decrease velocity significantly. That’s been confirmed by testing done by Bryan Litz’s Applied Ballistics Labs. There may be some minor speed loss.]

FirearmsID.com barrel rifling diagram
Many barrel-makers mark the twist rate and bore dimensions on their barrel blanks.

Think of it like tires on your truck. If you have a new set of tires put on your truck, and they balance them proper at the tire shop, you can drive down a street in town at 35 MPH and they spin perfect. You can get out on the highway and drive 65 MPH and they still spin perfect. A bullet acts the same way.

Once I loaded some 35gr HP bullets in a 22-250 Ackley with a 1:8″ twist. After putting three shots down range, the average velocity was 4584 FPS with an RPM level of 412,560. The group measured .750″ at 100 yards. This is a clear example that it is hard to over-stabilize a good bullet.

Twist-rate illustration by Erik Dahlberg courtesy FireArmsID.com. Krieger barrel photo courtesy GS Arizona.
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December 6th, 2022

How Barrel Twist Rates Can Affect Muzzle Velocities

applied Ballistics Barrel Twist rate velocity testing test bryan Litz
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.

applied Ballistics Barrel Twist rate velocity testing test bryan Litz

applied Ballistics Barrel Twist rate velocity testing test bryan Litz
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
Barrel Twist Rate Velocity Modern Advancements Book Bryan Litz Applied Ballistics

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).

Barrel Twist Rate Velocity Modern Advancements Book Bryan Litz Applied Ballistics

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.

Barrel Twist Rate Velocity Modern Advancements Book Bryan Litz Applied BallisticsThis 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.

Permalink Bullets, Brass, Ammo No Comments »
November 26th, 2022

How Humidity Affects Powder Performance — Important Podcast

Bryan litz science academy accuracy podcast book subscription membership

Bryan Litz and The Science of Accuracy Academy has released a new Podcast with vital information for all handloaders. This Podcast examines the effects of humidity variances on powder. Bryan notes: “If you want to know how much this can matter, we’re talking up to 200 fps difference for the same load of H4350 in 6.5 Creedmoor” at opposite extremes of humidity.

Bryan adds that “Most shooters don’t realize what a big deal this can be — it overshadows many of our efforts to make consistent velocity and hit targets. This can happen in loaded rounds not just for hand loading where you expose powder to ambient humidity. This is especially important for hunters considering the range of environments hunting ammo goes through.”

Bryan litz science academy accuracy podcast book subscription membership

25% Off Sale on The Science of Accuracy Academy Products

As a Black Friday/Cyber Monday promotion, The Science of Accuracy Academy is running a 25% OFF Sale on everything in the store, now through Monday, November 28, 2022. Save on Bryan Litz’s six impressive books about Ballistics, Bullet Performance, and Long Range Shooting. The Berger Bullets Reloading Manual is also discounted. Use Discount Code BF2022.

In addition you can get your own subscription to the Academy, allowing you to access all podcasts, exclusive videos, learning resources, and bullet data sheets.

Bryan litz science academy accuracy podcast book subscription membership
Permalink Hunting/Varminting, Reloading, Tech Tip No Comments »
November 22nd, 2022

Bullet Flight Video Reveals Shock Wave and Bullet Base Drag

Science Accuracy Academy bullet video Schlieren movie shock wave capture

Ever wondered what the air around a moving supersonic bullet really looks like? Check out this video from the Bryan Litz Ballistics Facebook page. This is a Schlieren video* of a 6mm 109gr Berger LRHT bullet at about 2800 fps as fired from Francis Colon’s PRS rifle at the Applied Ballistics Lab.


Bryan Litz notes: “You can clearly see the compression (shock) wave at the front of the bullet. A compression wave is formed when the air has to move faster than the speed of sound to get out of the way, which is certainly the case for this bullet which is moving about 2.5 times the speed of sound (Mach 2.5).

That shock wave is the ‘snap’ you hear when bullets fly past you if/when you’re downrange. Also, compressing the air into a shockwave takes energy, and that energy comes directly out of the forward velocity of your bullet and gets converted into heat and noise as the shock wave forms and dissipates.

The turbulent wake at the base of the bullet shows where/how base drag applies. The third and smallest component of drag for a supersonic bullet is skin friction drag, which is a viscous boundary layer effect, and is the least visible in this image. So as you head to the range or the hunting stand, think about the absolute violence your bullets are committing in the atmosphere, before they even reach the target!”

Subscribe to the Science of Accuracy Academy for more precision rifle and long range shooting content. LINK: TheScienceofAccuracy.com.

Science of Academy Contest
The Science of Accuracy Academy is currently running a contest for new subscribers. The winner receives a Vortex Fury HD 5000 Laser Rangefinder Binocular unit with Applied Ballistics functionality. Act soon — the deadline to enter is November 23, 2022 at 1:00 pm Eastern.

Science Accuracy Academy vortex rangefinder binoculars contest prize bryan litz


* Schlieren imaging makes air flow features visible. SEE Schlieren Photography Wikipedia page.

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November 13th, 2022

Effective Range and Lethality of Hunting Bullets Examined

hunting book Litz Lethality

Hunting season continues in many areas of the nation, so many game hunters have questions about terminal performance and particular caliber/cartridge combinations. Bryan Litz of Applied Ballistics says there are really a number of questions that need to be answered:

1) What’s the max range that the shooter/rifle is capable of hitting the intended target?

2) What’s the max range that a bullet can kill the intended game?

3) How do bullets kill?

4) Effects of Muzzle Velocity on Lethality.
(Your MV may be lower in winter with temp-sensitive powders).

5) Long Range Lethality and the Ballistic Coefficient.

Lethality hunting bullets litz bookYou’ll find answers to these and other questions in Bryan’s book, Applied Ballistics for Long-Range Shooting. These topics are covered in Chapter 15: Lethality of Long Range Hunting Bullets. Bryan says: “For responsible hunting, knowing your limits and your rifle’s limits, is important.”

Bryan’s book also includes Bullet Lethality Charts for a variety of calibers and cartridge types. These charts feature categories for 600-lb, 300-lb, and 150-lb Game animals so you can match performance to the size of your prey. Bryan explains: “If I wanted to know how a Medium Capacity Cartridge shooting the 6mm Berger 115 VLD will perform on 300-pound game, I can reference the bullet-specific chart.”

Lethality hunting bullets litz book

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October 31st, 2022

The “Mental Game” — Mantras for Competitive Shooting Success

shooting training applied ballistics bryan litz

Bryan Litz Applied Ballistics“Shoot Like a Champion”. Bryan Litz, author of Applied Ballistics for Long-Range Shooting, says he often sees notes like this tucked in shooter’s gear (or taped to an ammo box) at matches. What “marksmanship mantras” do you use? Do you have a favorite quote that you keep in mind during competition?

On the Applied Ballistics Facebook Page, Bryan invited other shooters to post the motivating words (and little reminders) they use in competition. Here are some of the best responses:


    “Shoot 10s and No One Can Catch You…” — James Crofts

    “You Can’t Miss Fast Enough to Win.” — G. Smith

    “Forget the last shot. Shoot what you see!” — P. Kelley

    “Breathe, relax, you’ve got this, just don’t [mess] up.” — S. Wolf

    “It ain’t over ’til the fat lady sings.” — J. McEwen

    “Keep calm and shoot V-Bull.” — R. Fortier

    “Be still and know that I am God[.]” (PS 46:10) — D.J. Meyer

    “Work Hard, Stay Humble.” — J. Snyder

    “Shoot with your mind.” — K. Skarphedinsson

    “The flags are lying.” — R. Cumbus

    “Relax and Breathe.” — T. Fox

    “Zero Excuses.” — M. Johnson

    “SLOW DOWN!” — T. Shelton

    “Aim Small.” — K. Buster

    “Don’t Forget the Ammo!” (Taped on Gun Case) — Anonymous

PARTING SHOT: It’s not really a mantra, but Rick Jensen said his favorite quote was by gunsmith Stick Starks: “Them boys drove a long ways to suck”. Rick adds: “I don’t want to be that guy”, i.e. the subject of that remark.

Permalink Competition, Shooting Skills 2 Comments »
October 14th, 2022

Avoid Having a ‘Train Wreck’ at the 2022 F-Class Nationals

train wreck Bryan Litz shooting tips ballistics

The 2022 NRA F-Class National Championships commence this weekend at the Ben Avery range in Phoenix, Arizona. The Mid-Range F-Class Nationals commence this Sunday, October 16, with practice on Saturday, October 15. The 1000-yard Long Range match starts on October 20th.

2022 NRA F-Class Nationals Ben Avery AZ train wreck Bryan Litz shooting tips ballistics

How to Avoid “Train Wrecks” In Competition

In any shooting competition, you must try to avoid major screw-ups that can ruin your day (or your match). In this article, past F-TR National Mid-Range and Long Range Champion Bryan Litz talks about “Train Wrecks”, i.e. those big disasters (such as equipment failures) that can ruin a whole match. Bryan illustrates the types of “train wrecks” that commonly befall competitors, and he explains how to avoid these “unmitigated disasters”.

Urban Dictionary “Train Wreck” Definition: “A total @#$&! disaster … the kind that makes you want to shake your head.”

train wreck Bryan Litz shooting tips ballisticsTrain Wrecks (and How to Avoid Them)
by Bryan Litz of Applied Ballistics LLC.

Success in long range competition depends on many things. Those who aspire to be competitive are usually detail-oriented, and focused on all the small things that might give them an edge. Unfortunately it’s common for shooters lose sight of the big picture — missing the forest for the trees, so to speak.

Consistency is one of the universal principles of successful shooting. The tournament champion is the shooter with the highest average performance over several days, often times not winning a single match. While you can win tournaments without an isolated stellar performance, you cannot win tournaments if you have a single train wreck performance. And this is why it’s important for the detail-oriented shooter to keep an eye out for potential “big picture” problems that can derail the train of success!

Train wrecks can be defined differently by shooters of various skill levels and categories. Anything from problems causing a miss, to problems causing a 3/4-MOA shift in wind zero can manifest as a train wreck, depending on the kind of shooting you’re doing.

Below is a list of common Shooting Match Train Wrecks, and suggestions for avoiding them.

1. Cross-Firing. The fastest and most common way to destroy your score (and any hopes of winning a tournament) is to cross-fire. The cure is obviously basic awareness of your target number on each shot, but you can stack the odds in your favor if you’re smart. For sling shooters, establish your Natural Point of Aim (NPA) and monitor that it doesn’t shift during your course of fire. If you’re doing this right, you’ll always come back on your target naturally, without deliberately checking each time. You should be doing this anyway, but avoiding cross-fires is another incentive for monitoring this important fundamental. In F-Class shooting, pay attention to how the rifle recoils, and where the crosshairs settle. If the crosshairs always settle to the right, either make an adjustment to your bipod, hold, or simply make sure to move back each shot. Also consider your scope. Running super high magnification can leave the number board out of the scope’s field view. That can really increase the risk of cross-firing.

2. Equipment Failure. There are a wide variety of equipment failures you may encounter at a match, from loose sight fasteners, to broken bipods, to high-round-count barrels that that suddenly “go south” (just to mention a few possibilities). Mechanical components can and do fail. The best policy is to put some thought into what the critical failure points are, monitor wear of these parts, and have spares ready. This is where an ounce of prevention can prevent a ton of train wreck. On this note, if you like running hot loads, consider whether that extra 20 fps is worth blowing up a bullet (10 points), sticking a bolt (DNF), or worse yet, causing injury to yourself or someone nearby.

train wreck Bryan Litz shooting tips ballistics

[Editor’s Note: The 2016 F-Class Nationals will employ electronic targets so conventional pit duties won’t be required. However, the following advice does apply for matches with conventional targets.]

3. Scoring/Pit Malfunction. Although not related to your shooting technique, doing things to insure you get at least fair treatment from your scorer and pit puller is a good idea. Try to meet the others on your target so they can associate a face with the shooter for whom they’re pulling. If you learn your scorer is a Democrat, it’s probably best not to tell Obama jokes before you go for record. If your pit puller is elderly, it may be unwise to shoot very rapidly and risk a shot being missed (by the pit worker), or having to call for a mark. Slowing down a second or two between shots might prevent a 5-minute delay and possibly an undeserved miss.

train wreck Bryan Litz shooting tips ballistics4. Wind Issues. Tricky winds derail many trains. A lot can be written about wind strategies, but here’s a simple tip about how to take the edge off a worse case scenario. You don’t have to start blazing away on the command of “Commence fire”. If the wind is blowing like a bastard when your time starts, just wait! You’re allotted 30 minutes to fire your string in long range slow fire. With average pit service, it might take you 10 minutes if you hustle, less in F-Class. Point being, you have about three times longer than you need. So let everyone else shoot through the storm and look for a window (or windows) of time which are not so adverse. Of course this is a risk, conditions might get worse if you wait. This is where judgment comes in. Just know you have options for managing time and keep an eye on the clock. Saving rounds in a slow fire match is a costly and embarrassing train wreck.

5. Mind Your Physical Health. While traveling for shooting matches, most shooters break their normal patterns of diet, sleep, alcohol consumption, etc. These disruptions to the norm can have detrimental effects on your body and your ability to shoot and even think clearly. If you’re used to an indoor job and eating salads in air-conditioned break rooms and you travel to a week-long rifle match which keeps you on your feet all day in 90-degree heat and high humidity, while eating greasy restaurant food, drinking beer and getting little sleep, then you might as well plan on daily train wrecks. If the match is four hours away, rather than leaving at 3:00 am and drinking five cups of coffee on the morning drive, arrive the night before and get a good night’s sleep.”

Keep focused on the important stuff. You never want to lose sight of the big picture. Keep the important, common sense things in mind as well as the minutia of meplat trimming, weighing powder to the kernel, and cleaning your barrel ’til it’s squeaky clean. Remember, all the little enhancements can’t make up for one big train wreck!

Permalink Competition, Shooting Skills, Tech Tip No Comments »
September 17th, 2022

Bullet Pointing 101 — How to Point Match Bullet Tips

Berger Bullet Pointing Applied Ballistics Bryan Litz Whidden Pointing Die pointer

Tech Tip by Doc Beech, Applied Ballistics Support Team
I am going to hit on some key points when it comes to bullet pointing. How much pointing and trimming needed is going to depend on the bullet itself. Specifically how bad the bullets are to begin with. Starting out with better-quality projectiles such as Bergers is going to mean two things. First that you don’t need to do as much correction to the meplat, but also that the improvement is going to be less. NOTE: We recommend you DO NOT POINT hunting bullets. Pointing can affect terminal performance in a bad way.

NOTE the change in the bullet tip shape and hollowpoint size after pointing:
Berger Bullet Pointing Applied Ballistics Bryan Litz Whidden Pointing Die pointer

Don’t Over-Point Your Bullets
What is important here is that you never want to over-point. It is far better to be safe, and under-point, rather than over-point and crush the tips even the slightest bit. To quote Bryan Litz exactly: “Best practice is to leave a tiny air gap in the tip so you’re sure not to compress the metal together which will result in crushing. Most of the gain in pointing is taking the bullet tip down to this point. Going a little further doesn’t show on target”. So in essence you are only bringing the tip down a small amount… and you want to make sure you leave an air gap at the tip.

Salazar Whidden Bullet Pointer system

Also keep in mind, bullet pointing is one of those procedures with variable returns. If you only shoot at 100-200 yards, bullet pointing will likely not benefit you. To see the benefits, which can run from 2 to 10% (possibly more with poorly designed bullets), you need be shooting at long range. Bryan says: “Typically, with pointing, you’ll see 3-4% increase in BC on average. If the nose is long and pointy (VLD shape) with a large meplat, that’s where pointing has the biggest effect; up to 8% or 10%. If the meplat is tight on a short tangent nose, the increase can be as small as 1 or 2%.” For example, If you point a Berger .308-caliber 185gr Juggernaut expect to only get a 2% increase in BC.

Berger Bullet Pointing Applied Ballistics Bryan Litz Whidden Pointing Die pointer

Should You Trim after Pointing?
Sometimes you can see tiny imperfections after pointing, but to say you “need” to trim after pointing is to say that the small imperfections make a difference. Bryan Litz advises: “If your goal is to make bullets that fly uniformly at the highest levels, it may not be necessary to trim them.” In fact Bryan states: “I’ve never trimmed a bullet tip, before or after pointing”. So in the end it is up to you to decide.

Pointing is Easy with the Right Tools
The process of pointing in itself is very simple. It takes about as much effort to point bullets as it does to seat bullets. We are simply making the air gap on the tip of the bullet ever-so smaller. Don’t rush the job — go slow. Use smooth and steady pressure on the press when pointing bullets. You don’t want to trap air in the die and damage the bullet tip. You can use most any press, with a caliber-specific sleeve and correct die insert. The Whidden pointing die has a micrometer top so making adjustments is very easy.

Bryan Litz actually helped design the Whidden Bullet Pointing Die System, so you can order the Pointing Die and Inserts directly from Applied Ballistics. Just make sure that you pick up the correct caliber sleeve(s) and appropriate insert(s). As sold by Applied Ballistics, the Whidden Bullet Pointing Die System comes with the die, one tipping insert, and one caliber-specific sleeve. To see which insert(s) you need for your bullet type(s), click this link:

LINK: Whidden Gunworks Pointing Die Insert Selection Chart

Permalink Bullets, Brass, Ammo, Reloading 6 Comments »