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.
One 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 Kestrel, or remember to mentally correct the radio station’s pressure, by 1″ per 1,000 feet.”
Winchester just unveiled a completely updated website at Winchester.com. The new, mobile-friendly website offers comprehensive information on Winchester ammunition. In addition, the upgraded Winchester website now boasts a full-featured, interactive Ballistics Calculator which runs on web browsers as well as mobile Apps. This new Ballistics Calculator offers an innovative “Shooter’s Eye View”, shown above. You can change the magnification level on the “scope”, and adjust variables (such as temp and range) using the red sliders. Try it out — it’s fascinating to see how the calculated Point of Impact moves as you adjust the sliders.
NEW Winchester Ballistic Calculator Features:
— Calculator provides precise trajectory for hundreds of cartridge types and bullet weights
— Calculator includes library of Ballistic Coefficients.
— Calculator offers visual graphs showing trajectories — with calculated point of impact as well as trajectory curve chart.
— Calculator variables include sight-in range, target range, air temperature, crosswind speed, sight height, and elevation.
— Calculator offers side-by-side comparisons among five separate rounds.
— Calculator offers detailed statistics chart for fine-tuning your shooting.
— Calculator can print handy, small Drop Chart you can attach to your rifle.
The Winchester Ballistic Calculator is available as a free download for iPhone and iPad through the Apple iOs app store, and for Android phones and tablets through Google Play.
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At the Berger SW Nationals this week in Phoenix, the nation’s top long-range shooters will try to put all their shots in the 10-Ring at 800, 900, and 1000 yards. A good foundation in ballistics is vital if you want to succeed in the long-range game.
How much do you know about BCs, Bullet Shapes, Trajectories, Wind Drift, and other things in the realm of External Ballistics? You can test your knowledge of basic Ballistics principles with this interactive quiz. The questions and answers were provided by Ballistics Guru Bryan Litz of Applied Ballistics LLC. Bryan is the author of Applied Ballistics for Long-Range Shooting and other popular resources in print, DVD, and eBook format. Have fun with our Quiz.
The Quiz contains ten (10) questions. When you complete all ten questions, you can see your results, along with the correct answers.
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Improve Your Hit Ratio by Using Wing Flags
It’s not unusual for varmint hunters to invest $3,000.00 in a custom rifle, pay thousands more for spotting scope and laser rangefinder, and spend countless hours loading ultra-precise ammo. Yet, when they head off to the prairie dog fields, they’ll omit an essential piece of gear that can make the difference between a hit and a miss.
We’re talking about windflags. Many casual shooters, varmint hunters, and even some “tactical” shooters disdain windflags as gadgets suited only for the accuracy-obsessed benchrest crowd. In fact, windflags are just as important for the varminter as for the benchrest competitor. You may think that you can easily notice a major wind shift. But consider this, a change from a light 2.5 mph left breeze to a 2.5 mph right is a 5 mile per hour switch. That is enough to make you miss a prairie dog even at just 200 yards.
Here’s a chart that shows the effect of a 5 mph full-value (i.e. 90-degree) wind change at various distances. The values assume a typical .250 G1 BC varmint bullet launched at 3500 fps at a 3″-wide critter (center hold).
You don’t need to spend a lot of money on windflags. Even a bit of surveyors’ tape on a post is better than nothing. A simple windflag, placed at your shooting station, helps minimize the effect of cross-winds. If you align your shooting position so the breeze is at your back you can shoot with greater confidence even in high winds. Watch the way the windflag blows, and shoot at the dog mounds that are directly downwind.
Our friend Boyd Allen offers another tip: “When you go varminting, be sure to bring some kind of portable target stand. Accuracy or zero problems are much easier to diagnose and remedy if you can set up a target at 100 yards. A simple wood, A-Frame design, hinged at the top, works well, stores flat, and is easy to build.”
Here’s a great tip from Forum member Greg C. (aka “Rem40X”). Greg has created a trajectory table with windage and elevation data for various distances and wind speeds. Greg prints out a compact version of his drop chart to place on his rifle. While many shooters tape a ‘come-up’ table on their buttstock, Greg has a better solution. He tapes the trajectory table to the outside of his front flip-up scope cover. This way, when he flips up the cover, his data is displayed for easy viewing right in front.
With your ‘come-up’ table on the flip-up cover you can check your windage and elevation easily without having to move up off the rifle and roll the gun over to look at the side of the stock. Greg tells us: “Placing my trajectory table on the front scope cover has worked well for me for a couple of years and thought I’d share. It’s in plain view and not under my armpit. And the table is far enough away that my aging eyes can read it easily. To apply, just use clear tape on the front objective cover.”
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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.
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Here’s an important technology for ranges concerned with over-flight risks. Regular Bulletin readers will recall that we recently warned of the dangers of bullets launched with a high trajectory. (READ Article.) With a muzzle elevation of just 5°, a conventional bullet can fly over 3000 yards, retaining enough energy to kill. General Dynamics has come up with a solution for live-fire training programs that don’t require long-range target engagements. General Dynamics’ Short Stop® ammunition launches bullets that literally drop out of the air within 600 meters. What’s the secret to the short flight? Read on…
Short Stop 5.56x45mm and 7.62x51mm Ammunition Trajectory
This illustration shows the trajectories of 5.56 and 7.62 Short Stop bullets (yellow zone) compared to conventional rifle projectiles (black lines). You can see the “flight cycle” is completely different.
Short Stop ammunition employs advanced polymer/copper composite bullets with molded “fins”. The bullets sort of look like the end of a Phillips screwdriver (except the fins have a slight twist near their base). This “twisted fin” design causes the bullets to yaw, and that, in turn induces aerodynamic drag — a lot of drag. The molded bullets are also much lighter than conventional bullets (of the same caliber). The reduced weight/density gives them less momentum, so they lose velocity more readily than normal bullets. The combination of the low mass and high drag makes these bullets drop from the air within 600m or so, living up to their “Short Stop” designation.
In an interview with NRABlog.com, General Dynamics Bus. Dev. Manager Ruben Regalado explained how the Short Stop ammunition works. With this design, he says, “You can do a lot of the training you would do with a ball round with no fear of overflight. It’s the fin that does it. Due to the nature of its composition [the bullet] is lighter than the standard projectile, but the magic is in the fin.”
There are many potential applications for Short Stop rounds according to NRABlog Editor Lars Dalseide: “Where do these rounds come into play? Anywhere. Anywhere there’s military training, law enforcement training, or basic target shooting taking place. And with the encroachment of communities surrounding your favorite neighborhood range, [projectiles] that drop out of the air at 600 meters means the risk of overflight is significantly reduced.” The polymer-composite bullets are also frangible, so there is less penetration of objects and less chance of ricochet.
“Smurf” Bullets for .50 Caliber AA Rifles
Bryan Litz of Applied Ballistics has seen ammo similar to Short Stops used in .50-caliber rifles for training purposes. Bryan tells us: “Similar rounds have been available for .50 cal for many years. We find [the spent bullets] on the range at Camp Grayling (a Michigan National Guard training facility where we hold 1000-yard matches). The .50 cal rounds use blunt plastic things (we call them ‘Smurf’ bullets) and they use them for practicing anti-aircraft shooting. Instructors put up an RC target drone and the Guardsmen shoot at it with the .50s using the short range ammunition.”
Bryan says these “short flight” bullets have an important purpose, though the applications remain limited. “These kind of projectiles are a good tool for applications where an adequate SDZ (Surface Danger Zone) cannot be secured for the range location. I just hope the application remains confined to only those places where it’s necessary, i.e. where the SDZ presents a problem. I would hate to see our bullet options be limited to something like this under the guise of ‘range safety’, where the SDZ is properly secured.”
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In our Shooters’ Forum, there was an discussion about a range that was threatened with closure because rifle over-shoots were hitting a farm building over two miles from the firing line. One reader was skeptical of this, asking “how’s that possible — were these guys aiming at the stars?” Actually, you may be surprised. It doesn’t take much up-angle on a rifle to have a bullet land miles down-range. That’s why it’s so important that hunters and target shooters always orient their barrels in a safe direction (and angle). Shooters may not realize how much a small tilt of the barrel (above horizontal) can alter a bullet’s trajectory.
How many degrees of muzzle elevation do you think it would take to hit a barn at 3000 yards? Ten Degrees? Twenty Degrees? Actually the answer is much less — for a typical hunting cartridge, five to seven degrees of up-angle on the rifle is enough to create a trajectory that will have your bullet impacting at 3000 yards — that’s 1.7 miles away!
Five degrees isn’t much at all. Look at the diagram below. The angle actually displayed for the up-tilted rifle is a true 5.07 degrees (above horizontal). Using JBM Ballistics, we calculated 5.07° as the angle that would produce a 3000-yard impact with a 185gr .30-caliber bullet launched at 2850 fps MV. That would be a moderate “book load” for a .300 Win Mag deer rifle.
Here’s how we derived the angle value. Using Litz-derived BCs for a 185gr Berger Hunting VLD launched at 2850 fps, the drop at 3000 yards is 304.1 MOA (Minutes of Angle), assuming a 100-yard zero. This was calculated using a G7 BC with the JBM Ballistics Program. There are 60 MOA for each 1 degree of Angle. Thus, 304.1 MOA equals 5.068 degrees. So, that means that if you tilt up your muzzle just slightly over five degrees, your 185gr bullet (2850 fps MV) will impact 3000 yards down-range.
Figuring Trajectories with Different Bullets and MVs
If the bullet travels slower, or if you shoot a bullet with a lower BC, the angle elevation required for a 3000-yard impact goes up, but the principle is the same. Let’s say you have a 168gr HPBT MatchKing launched at 2750 fps MV from a .308 Winchester. (That’s a typical tactical load.) With a 100-yard zero, the total drop is 440.1 MOA, or 7.335 degrees. That’s more up-tilt than our example above, but seven degrees is still not that much, when you consider how a rifle might be handled during a negligent discharge. Think about a hunter getting into position for a prone shot. If careless, he could easily touch off the trigger with a muzzle up-angle of 10 degrees or more. Even when shooting from the bench, there is the possibility of discharging a rifle before the gun is leveled, sending the shot over the berm and, potentially, thousands of yards down-range.
Hopefully this article has shown folks that a very small amount of barrel elevation can make a huge difference in your bullet’s trajectory, and where it eventually lands. Nobody wants to put holes in a distant neighbor’s house, or worse yet, have the shot cause injury. Let’s go back to our original example of a 185gr bullet with a MV of 2850 fps. According to JBM, this projectile will still be traveling 687 fps at 3000 yards, with 193.7 ft/lbs of retained energy at that distance. That’s more than enough energy to be deadly.
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The web-based JBM Ballistics Program is one of the most sophisticated and accurate ballistics calculators available — and it’s free. The latest version of the JBM Trajectory Calculator includes field-test-derived actual G7 BCs, as well as bullet drag data from Lapua’s Doppler radar testing. You can also change weather variables, and generate come-up tables for distances out to 3000 yards.
Whenever we have web access, the JBM program is our “go-to” resource for dependable ballistics calculations. In our experience, with most bullets, if you input all the correct variables for the JBM program, it should get you within 1/2 moa (2 clicks), at 600 yards.
New URLs for JBM Ballistics Calculators
With the release of the latest version of the JBM program, some URLs for the calculations pages have changed. You may want to update your bookmarks with the following web addresses:
Bryan Litz, chief Ballistician for Berger Bullets (and a trained rocket scientist) has authored an impressive new book: Accuracy and Precision for Long Range Shooting. Bryan’s new book is a companion to his successful treatise, Applied Ballistics for Long-Range Shooting. Now in its Second Edition, Litz’s Applied Ballistics book has become the “go-to” Ballistics book for precision shooters worldwide.
While Bryan’s first book covers the science of ballistics and trajectory calculation, his new book examines practical issues involved in long-range accuracy. Bryan explains: “In a nutshell, this book focuses on the uncertainties of practical shooting which affect hit percentage on various size targets. In other words, classic ballistics teaches you how to calculate windage and elevation corrections. This book will help you understand what your chances are of hitting a target under certain conditions, and how to improve those chances through training and design.
Practical Examples
Does a low ES/SD really make a difference at long range? Absolutely. In Chapter 6, you can see that reducing muzzle velocity variation from 20 fps Standard Deviation (SD) to 10 fps SD improves hit percentage on a 5″ circle at 500 yards from 83% to 93%.
Ever wonder how much spin drift, Coriolis affect, or using G1 vs. G7 BC’s affect your chances of hitting a target? In Chapter 10 for example, you’ll learn that ignoring spin drift in ballistic calculations reduces hit percentage on a 10″ target from 21% to 15% at 900 yards for a specified environment and cartridge.
The new book is divided into three main sections. Part 1 focuses on Precision, which explores how hit percentage is related group size. Litz explains the variable that affect group size: muzzle velocity variation, range estimation error, wind estimation error, and inherent rifle precision
Part 2 focuses on Accuracy, which is how well the group is centered around the aim-point. Topics include: leveling your sights, trajectory modeling and secondary effects, calibrating ballistic solutions, and live fire verification.
Part 3 focuses on Weapon Employment Zone (WEZ) analysis. WEZ evaluates firearm effectiveness in terms of hit percentage. The author applies WEZ in the contexts of score shooting, varmint and big game hunting, and tactical shooting. WEZ is also used to compare hit percentage for the 300 Win Mag vs. .338 Lapua Mag.
Book is 300-page, Hard-Cover Format
Accuracy and Precision for Long Range Shooting is a 6″x9″ hardcover book with 300 pages, and retails for $34.95. The book is currently at the printers, and should begin shipping by October 15, 2012. In the mean time, you can pre-order and save $5 off the regular $34.95 retail price.
A dedicated iPad version of Ballistic (‘Ballistic’ App), a full-featured ballistics calculator for the iPhone, is available for the growing numbers of iPad users. As with the iPhone version, ‘Ballistic’ App for the iPad is “powered by JBM Ballistics” so it offers very precise solutions — typically, at 600 yards, JBM will get you within two or three clicks, provided you have good bullet BC data and reliable MV from your chronograph.
The ‘Ballistic’ App for the iPhone and iPad features a library of over 3,100 projectiles; the library includes the latest 2010 commercial data and G7 military coefficients from Aberdeen Proving Grounds. Along with calculating bullet trajectories, this software has many extra features. There are several different target cards so you can input shot placement and scoring is calculated automatically. There is also a range log (for recording shooting sessions), a mildot and MOA range estimator, and a convenient load database for storing your reloading recipes.
Special features in the iPad edition of ‘Ballistic’ App include: fully integrated split-screen ballistics, favorites, and range log; full-screen, hi-resolution charts; ballistics calculations update automatically as you edit; larger target sizes in range log; and screens can rotate. The iPad Ballistic App (release 2.3.7) costs $19.99. The standard version for iPhone and iTouch units, costs $9.99. To learn more about this software, visit ballistic.zdziarski.com.
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There are a variety of ballistics programs that can be used with handheld PDAs, and even Apple iPhones. But Bryan Litz, author of the new Applied Ballistics for Long Range Shooting book, has come up with something bigger and better. Employing the powerful Texas Instruments (TI) Voyage 200 graphing calculator, Bryan has created a Mobile Ballistics Solution (MOBALL) that is more sophisticated (and accurate) than typical PDA-based programs.
MOBALL includes TI graphing calculator and ballistics software. Kestrel windmeter NOT included.
Bryan tells us: “The Mobile Ballistics Computer (MOBALL) was created for one purpose: to provide shooters with the most accurate and complete ballistic firing solution possible for application in the field.” MOBALL runs on a TI graphing calculator — a sturdy, stand-alone, non-network device. That means you don’t need long-term cell phone contracts, expensive data plans, or weekly OS “updates” and patches. The TI also delivers long run-time on ordinary AAA batteries. That’s a big advantage over most laptop computers, which run out of “juice” after only 4-5 hours in the field.
According to Bryan, what sets MOBALL apart from other “deployable” ballistics calculators is that: “MOBALL provides a complete ballistic solution, with the ability to account for every major and minor variable affecting a bullets trajectory. In addition to the standard variables like atmospherics, uphill/downhill angles and wind, MOBALL also has the ability to account for more subtle ballistic effects like spin drift, Coriolis effect, and multiple winds in up to 3 zones.”
Importantly, Bryan’s MOBALL device can employ Ballistic Coefficients (BCs) referenced to the G7 standard. Compared to the older G1 BC model, the G7 BC standard better matches the characterics of the long, boat-tail bullets actually used by long-range shooters. Trajectories calculated using the G7 BC are more accurate for long-range bullets because the G7 BC doesn’t vary with velocity like the conventional G1 BC.
At $290.00, MOBALL isn’t the least expensive option for a mobile ballistics device, but that price includes the TI Voyage 200 graphing calculator, worth $180.00 by itself. Bryan adds: “As already mentioned, the feature set is extensive, and the software is much more sophisticated than most ballistics programs designed for PDAs. The solution is VERY accurate (CLICK to download MOBALL Accuracy Report). Also, the TI Voyage 200 is an impressive device itself, capable of solving advanced engineering and math problems. If you’re a high school/college student, engineer, etc, the TI Voyage 200 can be used for many school and work tasks unrelated to ballistics.”
Save $20 on MOBALL and Ballistics Book Combo
As a special Holiday Offer valid through December 31, 2009, you can save money when purchasing MOBALL and Bryan’s Applied Ballistics book together. The book and MOBALL unit are being offered as a Holiday Combo Set for $309.95. That’s a $20 savings over the $329.95 cost of purchasing both book and MOBALL unit separately.
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One 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.
Improve Your Hit Ratio by Using Wing Flags
Here’s a great tip from Forum member Greg C. (aka “Rem40X”). Greg has created a trajectory table with windage and elevation data for various distances and wind speeds. Greg prints out a compact version of his drop chart to place on his rifle. While many shooters tape a ‘come-up’ table on their buttstock, Greg has a better solution. He tapes the trajectory table to the outside of his front flip-up scope cover. This way, when he flips up the cover, his data is displayed for easy viewing right in front.
This illustration shows the trajectories of 5.56 and 7.62 Short Stop bullets (yellow zone) compared to conventional rifle projectiles (black lines). You can see the “flight cycle” is completely different.
“Smurf” Bullets for .50 Caliber AA Rifles
In our Shooters’ Forum, there was an discussion about a range that was threatened with closure because rifle over-shoots were hitting a farm building over two miles from the firing line. One reader was skeptical of this, asking “how’s that possible — were these guys aiming at the stars?” Actually, you may be surprised. It doesn’t take much up-angle on a rifle to have a bullet land miles down-range. That’s why it’s so important that hunters and target shooters always orient their barrels in a safe direction (and angle). Shooters may not realize how much a small tilt of the barrel (above horizontal) can alter a bullet’s trajectory.
The web-based 
A dedicated iPad version of 
At $290.00, MOBALL isn’t the least expensive option for a mobile ballistics device, but that price includes the TI Voyage 200 graphing calculator, worth $180.00 by itself. Bryan adds: “As already mentioned, the feature set is extensive, and the software is much more sophisticated than most ballistics programs designed for PDAs. The solution is VERY accurate (
