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.”
On the Defensive Edge Website, 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.
» CLICK HERE to Download Full Article as Printable PDF
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.”
This Editor, as a life-long sailor, also has some suggestions about wind. Many folks may not realize that wind can cycle, both in direction and in speed (velocity). If you are patient, you should be able to sense the timing of the cycles, which will help you predict shifts in wind direction and velocity. While it is tempting to shoot in the lulls, sometimes the true wind vector (angle + speed) may be most constant when the wind is blowing stronger.
Another tip for hunters is to orient your shot, when possible, in alignment with the wind direction. Try to face into the wind, or have the wind at your back. This is especially effective when shooting in a varmint field. Use a string of tape on a pole to show wind angle. Then shoot directly into the wind or with the wind directly at your back. This will minimize horizontal deflection caused by the wind.
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!”
Wouldn’t it be nice to have a print resource at your fingertips that has hundreds of true-size cartridge illustrations, plus technical descriptions of thousands of popular cartridge types? That could be a real time-saver. It’s no wonder this book is an Amazon category best-seller.
If you’re a serious shooter, the latest 7th Edition of the Ammo Encyclopedia belongs in your library. Released in late 2022, this 928-page book is probably the most comprehensive and up-to-date book in print covering current and obsolete cartridge and shotshell types. The Ammo Encyclopedia is a massive resource work with 100+ chapters, covering thousands of handgun, rifle, and shotgun cartridges from the past century and a half. This 928-page edition includes over 150 new cartridge profiles. An expanded Trademark Index lists contact information for all current ammunition manufacturers.
One of the best features is a full-color section with actual size drawings of over 320 current rimfire/centerfire cartridges and shotshells. You won’t find that many “life-size” cartridge drawings in one place even on the internet. Cartridge profiles and ballistic charts have been expanded to include many new factory cartridges. An updated Cartridge Index lists both the standard and alternate names for each cartridge in chronological order. The authors have even included air rifle pellets and historical images and charts. This 928-page softcover book is now just $19.99 on Amazon, 60% off list price.
Comments from guys who bought the book:
“This book contains a vast array of information on many modern and even obsolete ammunition. Definitely recommend for any modern reloader novice or experienced.” – Duggaboy460
“It’s a great reference book for individuals who reload their own ammunition. There is a lot more info in this Edition. Everyone who likes this information should have it in their library.” – Reloader
“Very comprehensive with great photos and detailed information. A Must have for anybody with several guns/ammo.” – M.Ibarra
Over the past 12 months, this article was one of the TOP 20 most-read Daily Bulletin features. We’re reprising it today for those who may have missed it the first time. The above diagram comes from a TiborasurasRex YouTube Video comparing G1 and G7 BC models. CLICK HERE to watch the video.
The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.
Some readers are not quite sure about the difference between G1 and G7 models. One forum member wrote us: “I went on the JBM Ballistics website to use the web-based Trajectory Calculator and when I got to the part that gives you a choice to choose between G1 and G7 BC, I was stumped. What determines how, or which one to use?”
The simple answer is the G1 value normally works better for shorter flat-based bullets, while the G7 value should work better for longer, boat-tailed bullets.
G1 vs. G7 Ballistic Coefficients — Which Is Right for You?
G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. The G1 shape looks like a flat-based bullet. The G7 shape is quite different, and better approximates the geometry of a modern long-range bullet. So, when choosing your drag model, G1 is preferable for flat-based bullets, while G7 is ordinarily a “better fit” for longer, boat-tailed bullets.
Drag Models — G7 is better than G1 for Long-Range Bullets
Many ballistics programs still offer only the default G1 drag model. Bryan Litz, author of Applied Ballistics for Long Range Shooting, believes the G7 standard is preferrable for long-range, low-drag bullets: “Part of the reason there is so much ‘slop’ in advertised BCs is because they’re referenced to the G1 standard which is very speed sensitive. The G7 standard is more appropriate for long range bullets. Here’s the results of my testing on two low-drag, long-range boat-tail bullets, so you can see how the G1 and G7 Ballistic coefficients compare:
G1 BCs, averaged between 1500 fps and 3000 fps:
Berger 180 VLD: 0.659 lb/in²
JLK 180: 0.645 lb/in²
The reason the BC for the JLK is less is mostly because the meplat was significantly larger on the particular lot that I tested (0.075″ vs 0.059″; see attached drawings).
For bullets like these, it’s much better to use the G7 standard. The following BCs are referenced to the G7 standard, and are constant for all speeds.
Many modern ballistics programs, including the free online JBM Ballistics Program, are able to use BCs referenced to G7 standards. When available, these BCs are more appropriate for long range bullets, according to Bryan.
[Editor’s NOTE: BCs are normally reported simply as an 0.XXX number. The lb/in² tag applies to all BCs, but is commonly left off for simplicity.]
This article is copyright 2023 AccurateShooter.com. No 3rd Party republication of this article is allowed without advance approval and payment of licensing fees.
Tactical competitor Zak Smith stores his elevation and wind drift data on a handy laminated data card. To make one, first generate a come-up table, using one of the free online ballistics programs such as JBM Ballistics. You can also put the info in an Excel spreadsheet or MS Word table and print it out.
Above is a sample of a data card. For each distance, the card includes drop in inches, drop in MOA, drop in Mils. It also shows drift for a 10-mph cross wind, expressed in inches, MOA, and mils. Zak explained that “to save space… I printed data every 50 yards. For an actual data-card, I recommend printing data every 20 or 25 yards.” But Zak also advised that you’ll want to customize the card format to keep things simple: “The sample card has multiple sets of data to be more universal. But if you make your own data card, you can reduce the chance of a mistake by keeping it simple.”
Once you have the card you can fold it in half and then have it laminated at a local office store or Kinko’s. Keep this in your pocket, tape it to your stock, or tie the laminated card to your rifle. If you regularly shoot at both low and high elevations, you may want to create multiple cards (since your ballistics change with altitude). To learn more about ballistic tables and data cards, check out the excellent “Practical Long-Range Rifle Shooting–Part 1″ article on Zak’s website.
Scope-Cover Mounted Ballistics Table
Another option is to place your ballistics card on the back of the front flip-up scope cover. This set-up is used by Forum member Greg C. (aka “Rem40X”). With your ‘come-up’ table on the flip-up cover you can check your windage and elevation drops easily without having to move out of shooting position.
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.”
Lapua offers a FREE Ballistics App. This was the first mobile ballistics App utilizing the 6DOF calculation model, making it one of most accurate ballistics Apps on the market. With this free App you can calculate trajectories, range, bullet drop, turret adjustments and more. Lapua Ballistics offers up-to-date, Doppler-measured Lapua cartridge and bullet data. It also includes the option to define custom bullets manually.
Lapua’s sophisticated FREE Ballistics App has many great features — much more than you’d expect for a free App. If you do much shooting past 300 yards, or use a wide variety of bullets and/or cartridge types, definitely download the App and give it a try. For more details, read the Lapua Ballistics App User Manual. This handy PDF file explains how to set up the App and utilize all its powerful features.
Utilizes 6DOF, the most accurate calculation method
Always available with latest Lapua cartridge / bullet information
Quick and easy to change inputs like distance, wind speed and angle
Several result outputs available, with numerical, reticle, table and graph views
Create and clone your own firearm / reticle combinations
Choose between metric and imperial values
Set Point Blank-range to different sight-in distances and impact windows
Set Aiming point to moving target
Add custom bullets (calculations based on BC G1 or G7 and Siacci method)
Features include Sight-in-POI, Coriolis, Max Range and Cant Angle calculation
Compare up to 3 Lapua cartridge/bullet performances to each other
Custom trajectory tables
After downloading the FREE Lapua Ballistics App for Android device or Apple iPhone/iPad, you’ll want to access the Lapua Ballistics App Guide which shows how to use all the features and options. In addition, Lapua offers a handy FAQ Page with User Tips and Answers to frequently Asked Questions. After downloading the FREE App, you should definitely go to the FAQ page. It has helpful illustrations showing how to set up the App for your firearms and cartridge types. Also check out the page explaining the Sight-In POI feature which allows profiles of different bullet weights in the same firearm.
Watch Video for Explanation of Lapua Ballistics App Features
2025 Lapua Ballistics App Updates
Lapua has added some significant 2025 updates to its Ballistics App. New features include:
Range Presets: Create ranges, with angles, and quickly move between them. Output Units: Set the unit of the calculation output to clicks, MRAD, or MOA Device Compass for Shooting Direction: When getting wind data or getting location in Coriolis tab, shooting direction is taken from device compass. Wind Direction Correction: When changing shooting direction, ether by Coriolis tab or Get wind data button, wind direction is corrected by the new shooting direction.
Wouldn’t it be nice to have a print resource that has hundreds of true-size cartridge illustrations, plus technical descriptions of thousands of popular cartridge types? That could be a real time-saver. It’s no wonder this Ammo Encyclopedia book is an Amazon category best-seller.
If you’re a serious shooter, the latest 7th Edition of the Ammo Encyclopedia belongs in your library. This 928-page book by Charles Priore Jr. and Lisa Buening is probably the most comprehensive and up-to-date book in print covering current and classic cartridges and shotshells. The Ammo Encyclopedia is a massive resource work. The 7th Edition, released in October 2022, now boasts 100+ chapters, covering thousands of handgun, rifle, and shotgun cartridges. This 928-page softcover book sells for $39.99 on Amazon (#ad). That’s a good deal — 20% off list price.
One of the best features is a full-color section depicting actual size drawings of over 300 current rimfire/centerfire cartridges and shotshells. You won’t find that many “life-size” cartridge drawings in one place even on the internet. Cartridge profiles and ballistic charts have been expanded to include many new factory cartridges. An expanded Trademark Index lists contact information for all current ammunition manufacturers.
For the 7th Edition, over 150 cartridge types have been added. And dozens of previously proprietary cartridges now have individual profiles. An expanded color section shows current centerfire, rimfire, and shotshell cartridges in full color. Plus updated Ballistic Tables provide muzzle velocity, dimensions, and page numbers for the corresponding cartridge profile pages.
Comments from guys who bought the book:
“[The Ammo Encyclopedia is] better than Cartridges of the World. Much better editing and more accurate.” — John Guibert
“The amount and depth of detail provided is beyond impressive. An enormous amount of time and thought went into this latest version of the Ammo Encyclopedia.” — BW Kreisler
“I have many books on firearms and ammunition acculmulated over a few decades. This is by far the best and most comprehensive book on ammunition that I have ever seen. It is a must have reference source for everthing ammunition whether for current or obsolete and the history behind them.” – Eric
Today we share some smart tips from a past F-Class and Sling Champion who is both a great shooter AND a ballistics wizard. Founder of Applied Ballistics LLC, Bryan Litz is the author of multiple books and creator of advanced Ballistics Software.
Bryan is also a highly skilled competitor. In 2015, Bryan Litz won the F-TR Mid-Range AND Long-Range National Championships hosted at Ben Avery. And at the 2014 Berger SW Nationals (SWN), Bryan took top honors among all sling shooters. If you only know Bryan Litz from his Applied Ballistics Books and DVDs, you may not realize that this guy is a also great marksman along with being an actual rocket scientist!
Given his impressive track record in both F-Class and Palma (Fullbore) out to 1000 yards, we asked Bryan if he had any advice for other long-range competitors.
First Bryan provided three tips concerning Ballistics, his special area of expertise. Next Bryan offered three more general tips about long-range competition — how to analyze your shooting, how to choose your ‘wind strategy’, and how to avoid the most costly mistakes, i.e. how to avoid the “train-wrecks”.
Bryan Litz won the 2015 F-TR Mid-Range and Long-Range Championships with this sleek rig:
Litz Ballistics Tips
Ballistics TIP ONE. If you’re having trouble getting your ballistic software to match actual drops, you need to look at a number of possible reasons. Here are some common issues that can cause problems.
Click Values Are Not Exact. Scopes and iron sights don’t always produce accurate adjustments. In other words, if your ballistics program predicts 30 MOA of drop, and you dial 30 MOA but hit low, it might be that your sight actually only moved 28 MOA (for example). To see if your sight is adjusting accurately, shoot a tall target at 100 yards and measure group separation when dialing your sight.
Barometric vs. Station Pressure. This is a commonly misunderstood input to ballistics programs. You can avoid this pitfall by remembering the following: station pressure is the actual measured pressure at your location, and you don’t need to tell the program your altitude when using station pressure. Barometric pressure is corrected for sea level. If you’re using barometric pressure, you also have to input your altitude.
Muzzle Velocity. Chronographs are not always as accurate as shooters think they are — your true MV may be off by 10-20 fps (or more). If your drop is different than predicted at long range, it might be because your muzzle velocity input is wrong.
Mixing Up BC (G1 vs. G7). Knowledgeable long range shooters know that the G7 standard is a more representative standard for modern LR bullets. However, using G7 BCs isn’t just a matter of clicking the ‘G7′ option in the program. The numeric value of the BC is different for G1 and G7. For example, the G1 BC of the Berger 155.5 grain Fullbore bullet is .464 but the G7 BC is .237. If you were to enter .464 but click on G7, the results would be way off.
Ballistics TIP TWO. A properly installed level is absolutely essential for long range shooting. Without a good level reference, your long range wind zero will be off due to minor canting of the rifle from side to side. You can verify that your level is installed correctly on a 100-yard ‘tall target’. Draw a plumb line straight up the target and verify that your groups track straight up this line as you go up in elevation.
Ballistics TIP THREE. If your long range ballistic predictions aren’t tracking, always come back and verify your 100-yard zero. Sometimes a simple zero shift can be misconstrued as errors in long range ballistics predictions.
Litz Competition Shooting Tips
Competition TIP ONE. Improving your scores in long range competition is a constant process of self-assessment. After each match, carefully analyze how you lost points and make a plan to improve. Beginning shooters will lose a lot of points to fundamental things like sight alignment and trigger control. Veteran shooters will lose far fewer points to a smaller list of mistakes. At every step along the way, always ask yourself why you’re losing points and address the issues. Sometimes the weak links that you need to work on aren’t your favorite thing to do, and success will take work in these areas as well.
Competition TIP TWO. 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.
Competition TIP THREE. Actively avoid major train wrecks. Sounds obvious but it happens a lot. Select equipment that is reliable, get comfortable with it and have back-ups for important things. Don’t load on the verge of max pressure, don’t go to an important match with a barrel that’s near shot out, physically check tightness of all important screws prior to shooting each string. Observe what train wrecks you and others experience, and put measures in place to avoid them.
Looking down-range with F-TR rifle at Ben Avery Shooting Facility in Phoenix, Arizona.
Bullet Stability and Twist Rates
In this video, Bryan Litz talks about bullet in-flight stability and how to calculate barrel twist-rate requirements for long-range bullets. Bryan explains that bullet stability (for conventional projectiles) is basically provided by the spinning of the bullet. But this spin rate is a function of BOTH the nominal twist rate of the barrel AND the velocity of the projectile. Thus, when shooting the same bullet, a very high-speed cartridge may work with a slower barrel twist rate than is required for a lower-speed (less powerful) cartridge. For match bullets, shot at ranges to 1000 yards and beyond, Bryan recommends a twist rate that offers good stability.
You’ll find more expert information on long-range shooting and ballistics on the Applied Ballistics website and the Bryan Litz Ballistics Facebook page. Bryan’s most recent Facebook post talks about the Coriolis effect — the apparent drift of a rifle trajectory due to the rotation of the earth.
To learn more, we recommend you subscribe to the Applied Ballistics Science of Accuracy — with in-depth articles, brilliant podcasts, exclusive videos and more.
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!”
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.
The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). But that doesn’t mean you should select a G1 value simply because it is higher.
Drag Models — G7 is better than G1 for Long-Range Bullets
Scope-Cover Mounted Ballistics Table
