June 29th, 2015

Applied Ballistics Tests 50+ Types of .22 LR Rimfire Ammo

.22 LR Rimfire Ammunition testing Bryan Litz Applied Ballistics Eley
Photo shows Bryan Litz (on right) and tester Mitchell Fitzpatrick. Bryan said: “Only 2,445 rounds to go! We’re testing over 50 ammo types in five different twist barrels… science can be exhausting!”

Do you know the actual BC (Ballistic Coefficient) of your rimfire ammunition? Well Applied Ballisitics will soon have answers for you. Bryan Litz and his team of testers have been working on a Herculean project. They’ve been testing over fifty types of .22 LR ammo, using five different twist-rate barrels.

.22 LR Rimfire Ammunition testing Bryan Litz Applied Ballistics Eley

.22 LR Rimfire Ammunition testingBryan tells us: “We’re testing many types of .22 rimfire ammo for the next edition of the Ballistic Performance of Rifle Bullets book. We’re using a pair of Oehler chronographs to measure velocity at the muzzle (MV) and velocity at 100 yards.” With these numbers (average and SD) Bryan can calculate G1 BCs for all the 50+ types of rimfire ammo. What’s more, because every sample is shot through five different barrels (each with a different twist rate) Bryan can also determine how velocity is affected by twist rate.

The tests are primarily to determine velocities for BC calculations — this is not an accuracy test. Bryan explains: “Our tests are not really looking at accuracy, mainly because that’s so subjective to different rifles. Our testing is primarily focused on measuring the BC of rimfire rounds from different twist-rate barrels. The MVs and BCs from the different twist test barrels will be published in the upcoming second edition of Ballistic Performance of Rifle Bullets.

Will the rimfire data be added to the popular Ballistics Apps? That might happen in the future, says Bryan, but he’s not sure when: “We haven’t determined to add the .22 rimfire data to the ballistics Apps, but it’s a possibility.”

Bringing Science to the Rimfire World
Bryan’s goal with this project is to increase the rimfire knowledge base: “We hope to give the world of .22 LR rimfire a good dose of science. How is the BC of .22 rimfire ammo affected by barrel twist? Do subsonic rounds have more consistent BCs than supersonic or transonic rounds? What brands have the highest BCs? What brands have the most consistent MVs?”

.22 LR Rimfire Ammunition testing Bryan Litz Applied Ballistics Eley
Data from two Oehler chronographs is recorded in a computer. Ammo samples were tested in five (5) different barrels (of varying twist rates). Give credit to Dane Hobbs who supplied a test rifle, multiple barrels, and most of the ammo types for the test.

.22 LR at 300 Yards?
Bryan also conducted some longer range rimfire tests. His surprising findings might appear in the next volume of Modern Advancements in Long Range Shooting. Bryan notes: “While .22 rimfire isn’t typically considered ‘long range’, we were able to consistently hit a two-MOA steel target at 300 yards with the trajectory predicted by AB software and the measured BC of some standard .22 LR rimfire ammo. The info we’re generating may make it possible to push the range of target engagement for a round that’s not seen much advancement in many decades.”

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June 26th, 2015

New Version of AB Tactical App Released

Applied Ballistics Tactical AB App update

Applied Ballistics has just released a fully upgraded version of its popular Tactical App for Android devices. Bryan Litz tells us: “AB Tactical has received a major overhaul (including a new Bullet Library with over 420 options). The upgrade will require that you uninstall the previous version that you have of the application and then install this new version. This is due to the complete re-write of the internal database handling.” NOTE: You need to record your gun-specific data before you install the new version. Details of the updated AB Tactical App are featured in the new 19-page USER Manual.

NOTE: This upgrade is for the Applied Ballistics Tactical Version only. There is no iPhone version of this App, and this is not the standard app that can be purchased from Google Play, or iTunes.

The new version of AB Tactical has a host of important enhancements:

(more…)

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June 1st, 2015

Buell’s Beast: Heavy Artillery for ELR and 2-Mile Match

Darrell Buell ELR Rifle .376 Cheytac BAT Action 35
Click above image to view full-screen photo.

Our friend Darrell Buell has a new Beast — a monster 64-inch-long .375 CheyTac that weighs more than 70 pounds! Designed for ultra-long-range shooting (two miles and beyond), this beast represents the state-of-the-art in extreme long-range rifles.

Darrell Buell ELR Rifle .376 Cheytac BAT Action 35

Darrell reports: “This rifle is pretty much purpose-built to shoot 2+ miles extremely accurately. It is a .375 CheyTac (lengthened) built on a BAT 2.5″ action. The custom 35″, 1:10″-twist Brux barrel is a fat, 2″-diameter ‘straight taper’ with fluting. A custom 5″-long muzzle brake is fitted at the end. All barreled action work was done by R.W. Snyder Custom Rifles. The stock was created to fit the build by PDC Custom, and the massive muzzle brake as well.” The “bridge” at the end may look like a barrel block, but it’s not — the barrel completely free-floats. (The Picatinny rail on top of the bridge allows use of an overhanging bipod as an alternative to the JoyPod).

Darrell Buell ELR Rifle .376 Cheytac BAT Action 35
Darrell has lots of elevation on tap: “With 150 MOA in the Ivey rings, another 20 MOA in the scope rail, 55 MOA in the Nightforce Competition scope, and 10 MOA in the FCR-1 reticle, there’s an impressive +235 MOA available.”

(more…)

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May 19th, 2015

"How Do Bullets Fly?" — Great Online Resource

Bullet External Ballistics
“The overturning moment MW tends to rotate the bullet about an axis, which goes through the CG (center of gravity) and which is perpendicular to the plane of drag….

Ruprecht Nennstiel, a forensic ballistics expert from Wiesbaden, Germany, has authored a great resource about bullet behavior in flight. Nennstiel’s comprehensive article, How Do Bullets Fly, explains all the forces which affect bullet flight including gravity, wind, gyroscopic effects, aerodynamic drag, and lift. Nennstiel even explains the rather arcane Magnus Force and Coriolis Effect which come into play at long ranges. Nennstiel’s remarkable resource contains many useful illustrations plus new experimental observations of bullets fired from small arms, both at short and at long ranges.

Shadowgraph of .308 Winchester Bullet

Bullet External Ballistics

A convenient index is provided so you can study each particular force in sequence. Writing with clear, precise prose, Nennstiel explains each key factor that affects external ballistics. For starters, we all know that bullets spin when launched from a rifled barrel. But Nennstiel explains in greater detail how this spinning creates gyroscopic stability:

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May 3rd, 2015

.338 Lapua Magnum at 1.43 Miles — Video Shows Hits on Steel

Savage 110 BA .338 Lapua Magnum Berger Hybrid Bullets

Here’s a report posted by long-range shooter Grizzman on the LiveLeak video hosting site. Grizzman engaged an 18″x24″ steel target at the distance of 2530 yards — 1.43 miles. Grizzman produced a great video that really gives you a sense of the distance (see the zoom footage at the 0:30 time mark). At this distance, the ballistics are remarkable. Grizzman’s .338-cal, 300gr Berger Hybrid bullets went transonic at 2400 yards and dropped 228 feet (69.5 meters) over their 2530-yard trajectory.

WATCH Video — Second camera at target records bullet impacts (see and hear the hits):

You can see more Long-Range Shooting Videos on Grizzman’s Live Leak Channel. Among the interesting videos is a 1K Cinder Block Shoot: .338 LM Shoot Cinder Blocks at 1000 Yards.

(more…)

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April 22nd, 2015

Field Skills: Reading the Wind When Hunting

On LongRangeHunting.com, you’ll find a good article by Shawn Carlock about wind reading. Shawn is a veteran law enforcement marksman and a past USPSA national precision rifle champion. Shawn offers good advice on how to estimate wind speeds and directions using a multitude of available indicators — not just your wind gauge: “Use anything at your disposal to accurately estimate the wind’s velocity. I keep and use a Kestrel for reading conditions….The Kestrel is very accurate but will only tell you what the conditions are where you are standing. I practice by looking at grass, brush, trees, dust, wind flags, mirage, rain, fog and anything else that will give me info on velocity and then estimate the speed.”

Shawn also explains how terrain features can cause vertical wind effects. A hunter on a hilltop must account for bullet rise if there is a headwind blowing up the slope. Many shooters consider wind in only one plane — the horizontal. In fact wind has vertical components, both up and down. If you have piloted a small aircraft you know how important vertical wind vectors can be. Match shooters will also experience vertical rise when there is a strong tailwind blowing over an up-sloping berm ahead of the target emplacements. Overall, Shawn concludes: “The more time you spend studying the wind and its effect over varying terrain the more successful you will be as a long-range shooter and hunter.”

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March 19th, 2015

Terminal Ballistics — Video Explains Basic Principles

Terminal External Ballistics Exterior, Temporary Cavity Permanent Cavity

You’ve probably heard the term “Terminal Ballistics”. But do you really know what this refers to? Fundamentally, “Terminal Ballistics” describes the behavior of a projectile as it strikes, enters, and penetrates a target. Terminal Ballistics, then, can be said to describe projectile behavior in a target including the transfer of kinetic energy. Contrast this with “External Ballistics” which, generally speaking, describes and predicts how projectiles travel in flight. One way to look at this is that External Ballistics covers bullet behavior before impact, while terminal ballistics covers bullet behavior after impact.

The study of Terminal Ballistics is important for hunters, because it can predict how pellets, bullets, and slugs can perform on game. This NRA Firearm Science video illustrates Terminal Ballistics basics, defining key terms such as Impact Crater, Temporary Cavity, and Primary Cavity.

Terminal External Ballistics Exterior, Temporary Cavity Permanent Cavity

External Ballistics, also called “exterior ballistics”, is the part of ballistics that deals with the behavior of a non-powered projectile in flight.

Terminal Ballistics, a sub-field of ballistics, is the study of the behavior and effects of a projectile when it hits its target.

Terminal External Ballistics Exterior, Temporary Cavity Permanent Cavity

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March 4th, 2015

How Ballistic Coefficent Varies with Twist Rate (Stabilization)

By Bryan Litz, Applied Ballistics
Last month, in the Daily Bulletin, we talked about twist rate and muzzle velocity. That discussion was based on a detailed study published in Modern Advancements in Long Range Shooting.

More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.

Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:

Applied Ballistics used multiple barrels to study how twist rate affects BC.

stability gyroscopic ballistics coefficient drag twist rate

“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz

Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.

The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
stability gyroscopic ballistics coefficient drag twist rate

Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.

It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.

To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.


Learn More About SG and BC
Barrel Twist Rate Velocity Modern Advancements Book Bryan Litz Applied BallisticsThis article is just a brief overview of the interrelated subjects of twist rate, Gyroscopic Stability, and BC. The coverage of twist rates in Modern Advancements in Long-Range Shooting is more detailed, with multiple live fire tests.

Other chapters in the book’s twist rate section include:
· Stability and Drag – Supersonic
· Stability and Drag – Transonic
· Spin Rate Decay
· Effect of Twist rate on Precision

Other sections of the book include: Modern Rifles, Scopes, and Bullets as well as Advancements in Predictive Modeling. This book is sold through the Applied Ballistics online store. Modern Advancements in Long Range Shooting is also available in eBook format in the Amazon Kindle store.

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March 2nd, 2015

Bullet Sorting — Bryan Litz Offers Smart Advice

At the 2015 Berger Southwest Nationals, Forum member Erik Cortina cornered Bryan Litz of Applied Ballistics. Erik, the F-Open winner in the 600-yard Mid-Range match, was curious about bullet sorting. Knowing that bullets can be sorted by many different criteria (e.g. weight, overall length, base to ogive length, actual bearing surface length etc.) Erik asked Bryan to specify the most important dimension to consider when sorting. Bryan recommended sorting by “Base to Ogive”. Litz noted that: “Sorting by overall length can be misleading because of the nature of the open-tip match bullet. You might get a bullet that measures longer because it has a jagged [tip], but that bullet might not fly any different. But measuring base to ogive might indicate that the bullet is formed differently — basically it’s a higher resolution measurement….”

Ballistics Q & A in Shooter’s Forum
Got more questions about bullets? Our Shooters’ Forum has a special area for Bullets & Ballistics topics. There you can get your own questions about bullets and ballistics answered by Bryan Litz and other experts from Applied Ballistics.

accurateshooter.com forum bryan litz berger ballistics bullets

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February 17th, 2015

Brain Teaser: Do You Know the Rule of the Square?

wind drift wind reading 6mmbr rule of the squareHorizontal Wind-Drift vs. Distance
OK, here’s a challenge question for you.
Let’s see if you get it right.

Q: If the wind is blowing 10 mph from 9 o’clock and if my horizontal wind deflection is 0.7 inches at 100 yards, what is the horizontal drift at 1000 yards?

You may be thinking, “Well, since the target is ten times more distant, the wind-drift should be around 7 inches, maybe a little more since the bullet will be slowing down.” That sounds reasonable, right?

WRONG.

As you move from near to far, the increase in lateral deflection (from a 90° crosswind) is (roughly speaking) a function of the square of the multiple of distance. If your target is two times farther away, you use the square of two, namely four. If your target is five times farther away, you use the square of five, or twenty-five. In this example, the increased wind drift (from 100 to 1000 yards) is at least 0.7″ times (10 X 10) — over 70 inches (give or take a few inches depending on bullet type). We call that the Rule of the Square. This Rule lets you make a quick approximation of the windage correction needed at any yardage.

Precision Shooting and the Rule of the Square
I was going through some back issues of Precision Shooting Magazine and found many references to the Rule of the Square. This made me curious — I wondered how well the Rule really stacked up against modern ballistics programs. Accordingly, I ran some examples through the JBM Ballistics Trajectory Calculator, one of the best web-based ballistics programs. To my surprise, the Rule of the Square does a pretty good job of describing things.

EXAMPLE ONE — .308 Win (100 to 400 Yards)
For a 168gr Sierra MK (.308), leaving the muzzle at 2700 fps, the JBM-predicted values* are as follows, with a 10 mph, 9 o’clock crosswind (at sea level, 65° F, Litz G7 BC):

Drift at 100: 0.8 MOA (0.8″)
Drift at 200: 1.6 MOA (3.3″)
Drift at 400: 3.4 MOA (14.4″)

Here you can see how the Rule of the Square works. The rule says our drift at 200 yards should be about FOUR times the drift at 100. It the example above, 0.8″ times 4 is 3.2″, pretty darn close to the JBM prediction of 3.3″. Quoting Precision Shooting: “Note that the deflections at 100 yards are typically a quarter of those at 200; lateral deflections increase as the square of the range”. Precision Shooting, June 2000, p. 16.

EXAMPLE TWO — .284 Win (100 to 1000 Yards)
For a .284 Win load, with the slippery Berger 180gr Target Hybrids, the Rule of the Square still works. Here we’ll input a 2750 fps velocity, Litz G7 BC, 10 mph, 9 o’clock crosswind, (same 65° temp at sea level). With these variables, JBM predicts:

Drift at 100: 0.5 MOA (0.5″)
Drift at 500: 2.5 MOA (13.3″)
Drift at 1000: 5.9 MOA (61.3″)

Again, even with a higher BC bullet, at 1000 yards we end up with something reasonably close to the 100-yard deflection (i.e. 0.5″) multiplied by (10×10), i.e. 50 inches. The Rule of the Square alerts you to the fact that the effects of crosswinds are MUCH greater at very long range. In this example, our JBM-calculated drift at 1000 is 61.3″ — that’s over 100 times the 100-yard lateral drift, even though the distance has only increased 10 times.

Note that, even with a 5 mph 90° sidewind, the “Rule of the Square” still applies. The 1000-yard lateral deflection in inches is still over 100 times the lateral deflection at 100 yards.


Why This All Matters (Even in the Age of Smartphones)
wind drift wind reading 6mmbr rule of the squareNow, some would say, “Why Should I Care About the Rule of the Square? My iPhone has a Ballistics App that does all my thinking for me”. Fair enough, but knowledge of this basic Rule of the Square enables a shooter to make an informed guess about necessary windage even without a come-up sheet, as long as he knows the distance AND can fire a sighter at 100 or 200 yards as a baseline.

For example, if I see empirically that I need 1″ windage correction at 100 yards, then I know that at 600 yards I need at least roughly (6 x 6 x 1″) or 36 total inches of drift correction, or 6 MOA. (To be precise, 1 MOA = 1.047″ at 100 yards). I can figure that out instantly, even without a ballistics chart, and even if my Smartphone’s battery is dead.

*Values shown are as displayed on the JBM-figured trajectory tables. The numbers can be slightly imprecise because JBM rounds off to one decimal place for both inches and MOA.

Permalink Shooting Skills, Tech Tip 1 Comment »
November 17th, 2014

Sierra Infinity 7 Ballistics Software — Video Shows Features

Sierra Bullets has released Version 7 of its respected Infinity Exterior Ballistics software, available now for $39.95 for Windows computers. Renowned Sierra Ballistic Consultants Ted Almgren and Dr. Bill McDonald, who have written all Sierra Software since 1970, also wrote Infinity Version 7. Both are retired scientists from a major aerospace company. Infinity Exterior Ballistics Software version 7 is a sophisticated solver that can output multiple trajectory charts. A built-in database includes bullets and cartridges offered by 15 manufacturers, both U.S. and foreign.

This 13-minute Video Demonstrates the Many Features of Infinity 7 Ballistics Software:

This sophisticated program computes the effects on the bullet trajectory of variations in firing conditions. For example, you can change altitude of the firing point, target angle (uphill/downhill), wind speeds, or even modify the Ballistic Coefficient. In fact, you can change any inputted firing condition or combination of conditions.

One very handy function is the “back-to-zero” calculation. Infinity 7 software will compute where your gun is zeroed if you know that it shoots high by a measured amount at a known range.

Sierra Infinity software

Compare Trajectories with Five Different Bullets
One very powerful feature of Infinity 7 is its trajectory comparison capability. With most ballistics programs (such as the JBM online ballistics calculator), you can only view one bullet’s trajectory (and associated drop chart) at a time. Not so with Infinity 7. This software handles up to five different bullets at a time. You can compare downrange velocity, energy, drop, bullet path height, or crosswind drift with results shown in bolt tabular and graphical format. That helps you select the best bullet for your gun and application. The ability to compare downrange ballistics of five different bullets at once is particularly helpful for hunters, who can compare the “hitting power” of different projectiles at various distances.

You can purchase Infinity 7 Ballistics Software as a standalone product for $39.99, or you can buy the Infinity 7 Suite for $59.95, which includes the Sierra Bullets 5th Edition Reloading Manual on CD-ROM. If you prefer a printed loading Manual, a combo pack with Infinity 7 software CD-ROM plus published (hard-back) Reloading Manual is offered for $64.95.

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November 6th, 2014

Riding the Wave — Wind-Reading Advice from Mr. Salazar

German Salazar wind readingIn response to questions from a fellow F-Class shooter, German Salazar offered some expert advice in an article entitled: Basics: A Few Wind Reading Tips. Here are highlights from that essay. You can read the entire article on German’s Rifleman’s Journal Website. German cautions that: “I certainly am not attempting to make this short item into a comprehensive lesson in wind reading, but there may be a nugget or two in here for the newer shooter. There is, however, no substitute for range time and coaching.”

Preliminary Matters — Holding Off vs. Knob-Turning
Let’s begin by eliminating one topic altogether — I realize that the predominant method of wind correction in F-Class is holding-off with the crosshairs of your scope rather than adjusting the windage knob. I am a firm believer in aiming at the center and turning the knob as needed, but we’ll leave that for another time and focus on seeing what the wind is doing.

The Wave — Wind Cycles and Shot Timing
I find that most shooters begin to shoot immediately when the time commences rather than waiting for an appropriate moment in the cycle, this often leads to lost points early on. If you’ve been scoring prior to shooting, hopefully you’ve observing the flags and your shooter’s shot placement. It’s a very useful way of gaining some insight into the day’s wind patterns before shooting.

German Salazar wind readingMy technique is based on the understanding of wind as a cyclical wave motion. That statement alone should give you plenty to think about[.] Imagine for a moment, a surfer. He waits for a gentle swell, gets moving on it and rides it through it’s growth and ultimately its crescendo and hopefully avoids being swallowed in its crash. Wind typically behaves in the same fashion as that wave and a smart shooter behaves as does the surfer — get on early in the wave, ride through the major change and get off at the right moment. Knowing when to stop shooting is every bit as important as shooting quickly through the predictable portion of the wave; getting back on to the next wave is a matter of delicate judgment and timing.

When you are on that rising (or falling) wave, the idea is to shoot very quickly to minimize the amount of change between shots and to make a small adjustment on each shot. Too many shooters waste time trying to analyze the exact amount of the change, by which time it has changed even more! Get on with it, click or hold over a set amount and fire the next shot quickly. This is the foundation of how I shoot and it is very effective as long as you know when to start, when to stop and you have a good man working the target – a slow marker is the death of this method.

Watch Shots from Other Shooters
We all watch the wind flags, of course, and the trees if your range is so blessed (ours are fairly barren), and many other small wind indicators. Watching the shots of your fellow shooter can also be a very useful tool and should be observed whenever possible. When a good shooter next to you comes up with a poor shot, it should signal you to stop and reassess conditions as they may not be what they appear.

German Salazar wind reading

While scoring for another shooter, take a moment to scan the line of targets. You’ll be surprised at how most of the shot markers move in unison to one side and then the other. The sad truth is that most shooters are behind the changes in the wind and they will get carried to either side of the bull as the wind changes. You’ll see this in the targets as they come up, and once learned, you’ll find that the line of targets is as useful as another row of flags.

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October 21st, 2014

Shooting Skills: Reading the Wind When Hunting

Norway Hunting Snow

Thomas Haugland, a Shooters’ Forum member from Norway, is a long-range target shooter and hunter. He has created an interesting video showing how to gauge wind velocities by watching trees, grass, and other natural vegetation. The video commentary is in English, but the units of wind speed (and distance) are metric. Haugland explains: “This is not a full tutorial, but rather a short heads-up to make you draw the lines between the dots yourself”. Here are some conversions that will help when watching the video:

.5 m/s = 1.1 mph | 1 m/s = 2.2 mph | 2 m/s = 4.5 mph
3 m/s = 6.7 mph | 4 m/s = 8.9 mph | 5 m/s =11.2 mph

More Interesting Videos from Norway
There are many other interesting videos on Haugland’s YouTube Channel, including Game Stalking, Precision Reloading, and Tips on how to use a Mildot Reticle on a scope with MOA-based clicks.

Permalink - Videos, Hunting/Varminting, Shooting Skills 3 Comments »
October 19th, 2014

How Altitude and Air Pressure Influence Ballistics

Suunto AltimeterOne of our readers asked “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, the bullet behaves as if it has a higher ballistic coefficient.

Forum member Milanuk explains that the key factor is not altitude, but rather air pressure. Milanuk writes:

“In basic terms, as your altitude increases, the density of the air the bullet must travel through decreases, thereby reducing the drag on the bullet. Generally, the higher the altitude, the less the bullet will drop. For example, I shoot at a couple ranges here in the Pacific Northwest. Both are at 1000′ ASL or less. I’ll need about 29-30 MOA to get from 100 yard to 1000 yards with a Berger 155gr VLD @ 2960fps. By contrast, in Raton, NM, located at 6600′ ASL, I’ll only need about 24-25 MOA to do the same. That’s a significant difference.

Note that it is the barometric pressure that really matters, not simply the nominal altitude. The barometric pressure will indicate the reduced pressure from a higher altitude, but it will also show you the pressure changes as a front moves in, etc. which can play havoc w/ your calculated come-ups. Most altimeters are simply barometers that read in feet instead of inches of mercury.”

As Milanuk states, it is NOT altitude per se, but the LOCAL barometric pressure (sometimes called “station pressure”) that is key. The two atmospheric conditions that most effect bullet flight are air temperature, and barometric pressure. Normally, humidity has a negligible effect.

It’s important to remember that the barometric pressure reported on the radio (or internet) may be stated as a sea level equivalency. So in Denver (at 6,000 feet amsl), if the local pressure is 24″, the radio will report the barometric pressure to be 30″. If you do high altitude shooting at long range, bring along a Kestral, or remember to mentally correct the radio station’s pressure, by 1″ per 1,000 feet.”

You can do your own experimental calculations using JBM Online Ballistics (free to use). Here is an extreme example, with two printouts (generated with Point Blank software), one showing bullet trajectory at sea level (0′ altitude) and one at 20,000 feet. For demonstration sake, we assigned a low 0.2 BC to the bullet, with a velocity of 3000 fps.

Trajectory of Bullet fired at Sea Level

Trajectory of Bullet fired at 20,000 feet

if you want to learn more about all aspects of External Ballistics, ExteriorBallistics.com provides a variety of useful resources. In particular, on that site, Section 3.1 of the Sierra Manual is reprinted, covering Effects of Altitude and Atmospheric Pressure on bullet flight.

Permalink Tech Tip 5 Comments »
October 2nd, 2014

World’s Most Expensive Scope? $12K Hensoldt 6-24x72mm SAM

When does a scope cost as much as a new Harley-Davidson? When it is a top-of-the-line 72mm Hensoldt (by Zeiss). The remarkable Hensoldt ZF 6-24x72mm SAM scope integrates ultra-bright apochromatic fluorite glass with a calculator module that provides ballistic info and weather data to the shooter. This 6-24x72mm SAM Hensoldt may be the most advanced riflescope on the planet. With a street price of $11,982.00, it is certainly one of the most expensive. Take a 360° tour with this cool video from Hensoldt Zeiss.

Please enable Javascript and Flash to view this VideoPress video.

Hensoldt ZF 6-24x72mm SAM
SAM stands for “Sniper Auxiliary Module”. An integrated ballistics calculator can be programmed for up to four different types of ammo. Sensors in the integrated ring mount measure weather parameters. These values, as well as scope data, are then directly projected into the visual field of the eyepiece. This provides selectable displays of elevation clicks, windage clicks, angle of fire, cant angle, temperature, and air pressure.

Hensoldt Zeiss

Hensoldt Zeiss

Hensoldt Zeiss

Permalink Gear Review, Optics 6 Comments »
October 1st, 2014

Long Range Shooting Made Easy (New Video)

Accuracy 1st Development Group, a training operation based in Texas, will soon release a new instructional video: Long Range Made Easy. This training video features Bryan Litz, author of Applied Ballistics for Long Range Shooting. Many of the shooters shown in the video use the new ABM ammo developed by Bryan’s Applied Ballistics lab for Berger Bullets. Check out the preview “trailer” for Long Range Made Easy.

Watch Trailer for “Long Range Made Easy”

Accuracy 1st Development Group

Accuracy 1st Development Group

Accuracy 1st Scope Levels
Accuracy 1st also sells some interesting products for precision rifle shooters. Check out this unique, curved-vial scope leveler ring. More precise and sensitive than other scope levels, the Accuracy 1st leveling device can detect 1° of cant. Displayed line increments represent 2.5° of cant.

Scope Level – Tan Matte Teflon
Including 30mm Reducer Ring
Scope Level – Black Anodized Aluminum
34 Ring Size
Scope Lever Ring Accuracy 1st Scope Lever Ring Accuracy 1st

You may wonder: “Why are these scope levels better than other similar products?” Accuracy 1st explains: “Our levels are of the highest quality and accuracy. Some scope level manufacturers use plastic housings, air bubbles and sub-par glass in their vials. In lieu of a straight bubble vial, Accuracy 1st utilizes a custom curved vial featuring medical-grade glass and a ceramic ball. The use of the ceramic ball eliminates the inherent flaws associated with air bubble levels, which at higher temperatures and pressure will compromise the bubble size causing level inaccuracies. Typically air bubble levels require 3° to 5° [tilt] to even register movement. By contrast, the Accuracy 1st custom level will read movement at a minimum of 1° and will extend measurements out to +/- 10°.”

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September 26th, 2014

Norma’s “Ammo Academy” Provides Valuable Information

If you haven’t visited the Norma website recently, you should click over to www.norma.cc/en/ (the ‘en’ is for English version). There you will find Norma’s “Ammo Academy”, a technical resource that provides information on: Ballistics, Powder Storage, Barrel Wear, and Bullet Expansion. In addition, the Ammo Academy now links to Norma’s Reloading Data Center, where you’ll find loads for nearly 70 cartridge types including: .223 Rem, .22-250, 6mmBR Norma, 6XC, 260 Rem, 6.5-284, 6.5×55, 7mm-08, .270 Win, .284 Win, .308 Win, .30-06, 300 Win Mag, .338 Lapua Mag and dozens more.

Norma web site Ammo Academy

The Ammo Academy’s Ballistics section contains some fascinating technical facts:

stopwatch

  • After the trigger is pulled, it takes around 0.005 seconds before the firing pin reaches the primer.
  • From the firing of the primer it takes 0.0015-0.002 seconds until the bullet exits the muzzle.
  • When the bullet leaves the muzzle, the hot gases surround and overtake the bullet, continuing the acceleration for a few centimeters.
  • Because the barrel is always angled slightly upwards, the bullet’s flight starts about 3-5 cm below the line of sight.

Norma also offers some good advice about Powder and Cartridge Storage:

To maintain the product quality for as long as possible, you have to keep the powder in a suitable place under suitable conditions. Where possible, store the powder at a constant temperature, ideally between 12 and 15°C (54°F to 59°F), and a relative humidity of 40–50%. If the air is too dry, it will dry out the powder, which will cause the pressure to be higher, thus affecting performance. Also make sure that you close the powder container properly afterwards. Cartridges should be stored under the same ambient conditions to maintain their quality.

For more info on Norma products, CLICK HERE to access Norma’s Catalog Download Page.

Story Tip by EdLongrange. We welcome submissions from our readers.
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August 9th, 2014

“Firearm Science” Video Shows the Process of Zeroing Rifle

Most of us can figure out how to zero our rifles at 100 yards. But do you know how to get a solid zero at long range — as far as 1000 yards? You need to know your ballistics, otherwise you may waste a lot of ammo “sprayin’ and prayin'”. You definitely need to know your exact muzzle velocity, within a few FPS. This is not as simple as it seems, because it is not uncommon for chronograph results to be off by 10 to 20 fps or more, just through calibration error. Accordingly, you may want to test with a pair of chronos and record the results from each (you may be surprised at the variances).

scope turret elevation nightforceVideo Illustrates Zeroing Process
The process of zeroing rifles for long range is covered in a new “Firearm Science” video from the NRA. This video features George Reinas, a popular competitor on the Top Shot TV Show. George demonstrates how to adjust his scope to compensate for bullet drop at long range. Our friend Dennis Santiago was involved in the making of this video, which was filmed at the Burbank Rifle & Revolver Club in Southern California. The video is narrated by the talented Jessie Duff, one of America’s best action shooters.

scope turret elevation nightforceWhen zeroing at long range, you should first consult a good ballistics program. Select your baseline zero distance (such as 100 yards), then plug in the MV along with salient environmental factors: Altitude, Air Pressure, Temperature, Humidity. After you enter bullet BC, your ballistics program will calculate the drop to the target, expressed in MOA or Mils. Some programs will actually list the number of clicks up from your current zero.

You can print out the data from your ballistics solver as a “drop chart” that can be attached to your rifle stock. If you shoot at various altitudes you may need multiple drop charts.

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July 22nd, 2014

Zeiss Ballistics Calculator Mobile App for Android and iOS

Zeiss mobile ballistics appCarl Zeiss Sports Optics (Zeiss) has a new mobile Ballistics Calculator App for iOS (Apple) and target="_blank">Android devices. Modeled after the web-based Zeiss Ballistics Calulator, the new Mobile App is tailored to work precisely with Zeiss Ballistic reticles. Mike Jensen of Carl Zeiss Sports Optics explained: “We wanted those who use our proprietary ballistic reticles to have a ballistic tool that could be used virtually anywhere you have a signal for your device.”

The Zeiss Ballistic Calculator App allows users to pick their ballistic reticle from a drop-down menu. The user also has the ability to select factory or hand load data as well as environmental variables, and then the system will calculate and display the optimum magnification setting. With this system, distant yardages now coincide with the Zeiss ballistic reticle subtensions. The system allows the user to adjust standard settings for altitude and temperature, as well as other advanced settings, e.g. for muzzle velocity and sight height above bore.

Zeiss Ballistics Calculator App Features:

– One page screen application for fast data entry and easy to read results.

– Comprehensive and current database for factory and hand-loaded ammunition.

– Adjustable settings to customize unique shooting environments.

– Slide feature to visualize how magnification change alters point of impact.

Zeiss mobile ballistics app

The Zeiss Mobile Ballistic Calculator App can be downloaded at target="_blank">Google Play (Android App) and iTunes (iPhone App) for $4.99. Zeiss has noted that the App will soon be updated to include the Zeiss ASV ballistic turret system.

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June 26th, 2014

Modern Advancements in Long Range Shooting — By Bryan Litz

Litz Applied Ballistics Book Modern Advancements Long Range ShootingApplied Ballistics, LLC is offering an all-new book by Bryan Litz, the first in a series. The new 339-page, hard-cover book, Modern Advancements for Long Range Shooting, Volume I, documents the ongoing R & D being done at the Applied Ballistics laboratory, the “Area 51″ of the shooting world.

“This new series is heavily based in experimental ballistics, and takes a ‘Myth Busters’-type approach to many of the questions and problems faced by modern long range shooters,” stated Litz. Volume I of the series is scheduled for release in late July, 2014. The book will cost $39.95, but you can pre-order now for $35.95, a 10% savings.

Bryan adds: “Anyone interested in the underlying science behind shooting can benefit from this book. We address the important questions… How much does faster twist affect MV? How does stability affect BC from the muzzle and downrange? What chronographs are capable of high accuracy and precision? What characteristics should you look for in your long range rifle and optic set up? What new gadgets are being developed to enhance long range shooting?

New Book Features Extensive Live-Fire Test Results
Bryan tells us: “The book spotlights state-of-the-art technologies (and methodologies) in long range shooting. New equipment and old ideas are explored using experimental, live-fire testing. Extensive test results are reported in an easy-to-understand way. Among other things, our tests explore the effects of twist rate on muzzle velocity, BC (supersonic and transonic), precision, even spin rate decay for various rifling profiles as they are tested experimentally.

Chronographs and Optics Are Tested and Compared
Litz’s new book traces the evolution of modern rifle, bullet, and optic design. Results from chronograph comparison tests are presented, showing the strengths and weaknesses of available commercial chronographs. High-tech instrumentation such as laser rangefinders and wind measurement devices are explained in detail by contributing author Nick Vitalbo.

The New Book Puts Theory into Practice
We asked Bryan Litz how this new book differs from his previous treatises. Bryan replied: “My original Applied Ballistics for Long-Range Shooting book explains the fundamental elements of external ballistics. It’s the academic background which all future work relies on. The new book, Modern Advancements in Long Range Shooting, covers the ongoing development of equipment and ideas. We explore things like twist rate effects, modern rifle and optic design, and some of the high tech instruments which are being used to enhance the effectiveness of long range shooting.

Litz Applied Ballistics Book Modern Advancements Long Range Shooting

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