There are 7 different mathematical models for ballistics named G1 to G7. BC might sound like a bunch of hooey, but it’s really at the heart of bullet performance. The ballistic coefficient is measured in the units kg/m² or lbs/in². Ballistic Coefficient (0. 050 Bullet Weight: 750 gr Initial Velocity: 2820 fps Sight Height : 1. A pellet of the same caliber that weighed half as much (SD = 0. Estimation of the ballistic coefficient of cast bullets is nearly as accurate as with the jacketed bullets, and the calculations give reasonably good and comparative estimates of G1 ballistic coefficients. 040 at 900 fps, since BC is proportional to SD. 0 gr) [220. 5 in Shooting Angle: 0° Wind Speed: 10 mph Wind Angle: 90° Zero Range: 100 yd Chart Range: 1000 yd Maximum Range: 5196 yd Step Size: 100 yd: International Standard Atmosphere Altitude: Sea Level (0 ft) Barometric Pressure: 29. Important: Since there are thousands of bullet shapes the Ballistic Coefficient calculations made below are not 100% accurate, if you are shooting out past 400-500+ yards your going to need to get the exact BC from the bullet's manufacturer. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet G1 vs. Spitzer. G1 and G7 are different ways of representing what the ballistic coefficient (BC) of a bullet is. It is a great investment if you want to get into long range shooting and will The G7 standard projectile more closely represents today’s boat tail bullets and assigns them a more realistic BC than does the G1. 75 (1,954 fps @ ICAO Standard Atmosphere) BC values are also available. The ballistic coefficient related to the G1 model is also known as the G1 ballistic coefficient. G1 and G7 are two different methods of calculating Ballistics. It represents the drag characteristics of older, non-boat-tail bullet Ballistic Coefficients are measures of objects’ abilities to overcome air resistance mid-flight. The B. This was done to represent use by the average shooter. Understanding Bullet BC (Ballistic Coefficient) We hunters love to argue endlessly about calibers, cartridges, bullet weights, and muzzle velocities, but we should be equally concerned with BCs — Ballistic Coefficients. G1 and G7 do not directly describe the shape of a bullet. As Hornady moves the The G7 standard projectile more closely represents today’s boat tail bullets and assigns them a more realistic BC than does the G1. G1 projectiles are flat based bullets such as spritzer bullets, where G7 projectiles are going to cover boattail spitzers. 05) but with the same Cd and velocity, should be described as having a BC(GA) = 0. The result is a bullet that ˜ies true, penetrates G1 is most commonly used because it’s the old standard and the industry has not adapted to the more modern incarnations. The better, up-to-date ballistics programs let you select either G1 or G7 Ballistic Coefficient (BC) values when calculating a trajectory. To find the correct BC (some scientists would call it drag coefficients), Hornady now publishes “200 yard” Mach 2. 92 Hg G1 projectiles are flat based bullets such as spritzer bullets, where G7 projectiles are going to cover boattail spitzers. A ballistic standard such as the G1 or GA is a model of a projectile shape from which the drag and BC can be calculated. The problem herein lies that Berger Bullets aren’t standard projectiles. 0 ft/s) [3000. Our flat based bullets only have a G1 coefficient while our boat tails will have both G1 and G7 coefficients. 395 Bullet Weight: 75 gr Initial Velocity: 2790 fps Sight Height : 1. 0 to 4800. G1 vs. Typically, the higher the number, the lower the drag of the projectile (low negative acceleration), and the better the bullet will cut through the air. In regards to their BC a spitzer bullet has a high coefficient and is suitable for long-range shots, and the boattail spitzer is even superior making it one of the best bullets for long-range targets exceeding 1,000 yards. For example, a G1 BC is comparing the drag of that specific bullet to the G1 standard bullet. The G1 BC has traditionally been the ‘standard projectile’ used to define BCs for the entire sporting arms industry. 25 (2,512 fps @ ICAO Standard Atmosphere**) G1 and G7 Ballistic Coefficient (BC) numbers for all A-Tip®, ELD-X, and ELD Match bullets. Note the G1 uses the Drag Coefficient of . 0] Velocity (500. In ballistics, the ballistic coefficient (BC, C b) of a body is a measure of its ability to overcome air resistance in flight. Ballistic Coefficient (Velocity) Calculate a ballistic coefficient from near velocity, far velocity and distance between velocity measurement points. NOTE: These HAM Ballistic Coefficients were each generated by shooting a sample of 10 un-selected pellets straight from the tin. As Hornady moves the A Ballistic Coefficient (BC) is a number used to describe the drag on a bullet compared to some standard bullet. 0 to 15000. As Hornady moves the The difference between G1 BC and G7 BC is that the G7 BC is more representative of modern long-range bullets. Explanation of terms. 308] Bullet Weight (5. Most importantly, the G7 also renders an accurate BC at all velocities for a boat tail rifle bullet. 162 Bullet Weight: 230 gr Initial Velocity: 840 fps The two most important variables are the Initial Velocity and the Ballistic Coefficient. The G7 standard projectile more closely represents today’s boat tail bullets and assigns them a more realistic BC than does the G1. Shape (form factor) is one thing that goes into working out what BC is using either the G1 or G7 models. Thus, bullet makers are beginning to offer us G7-based BCs. 5 will experience less drag and retain its velocity better than one with a ballistic coefficient of 0. You've probably seen that G7 values are numerically lower than G1 values for the same bullet (typically). Ballistic Coefficient (B. 92 Hg Ballistic Coefficients are measures of objects’ abilities to overcome air resistance mid-flight. Ballistic Coefficients are measures of objects’ abilities to overcome air resistance mid-flight. 100 to 2. 5 in Shooting Angle: 0° Wind Speed: 0 mph Wind Angle: 90° Zero Range: 25 yd Chart Range: 500 yd Maximum Range: 3686 yd Step Size: 25 yd: International Standard Atmosphere Altitude: Sea Level (0 ft) Barometric Pressure: 29. 0 (2,233 fps @ ICAO Standard Atmosphere) and Mach 1. The G1 model is the most popular and is used for the flat base and ogive nose projectiles. 3. With the right BC you can make a What are the differences between G1 and G7 ballistic coefficient models, and when should each be used? Understanding the distinctions between G1 and G7 BC models is vital for accurate trajectory predictions: G1 Model: G1 is a traditional model designed for flat-based bullets. This hefty 7000 grain (1lb) projectile is basically what most small-arms projectiles today are measured against for their ballistic coefficient reference numbers. Mach 2. As Hornady moves the In ballistics, the ballistic coefficient (BC, C b) of a body is a measure of its ability to overcome air resistance in flight. 273. G1 is the old system for measuring BC and is suitable for flat based bullets, but many bullet manufacturers use this coefficient for boat tail bullets as well, so we include . The downside is, of course, inconsistent BC as velocity changes. The G1 is a model of a short, flat-bottomed Ballistic Coefficients are measures of objects’ abilities to overcome air resistance mid-flight. For this example, the best match would be to quote the ballistics coefficient as BC(G1) = 0. 5 in Shooting Angle: 0° Wind Speed: 0 mph Wind Angle: 90° Zero Range: 200 yd Chart Range: 200 yd Maximum Range: 10198 yd Step Size: 20 yd: International Standard Atmosphere Altitude: Sea Level (0 ft) Barometric Pressure: 29. If you do not have a Shooting Chronograph, I strongly suggest you purchase one. C. The G1 and G7 ballistic coefficients measured by Litz have been published in his excellent . It is inversely proportional to the negative acceleration: a high number indicates a low negative acceleration—the drag on the body is small in proportion to its mass. g” for a number of bullets, including most of the . The ballistic coefficient (BC) of a body is a measure of its ability to overcome air resistance in flight. Ballistic coefficient has units of lb/in² or kg/m². As Hornady moves the G1 is most commonly used because it’s the old standard and the industry has not adapted to the more modern incarnations. 010 to 2. ) is the numerical evaluation of a projectile’s efficiency in flight. By considering these factors, ballistic coefficients can be calculated for different bullets, allowing shooters to compare their performance and choose the best one for their needs. 5 and the G7 used the Stream line Body of almost 0. 085 at 900 fps. Because of our structured testing, HAM BCs are comparable against each other. Ballistic coefficient is calculated for input drag function. For this reason, and because these BCs The G1 projectile was one pound in weight (lead), and was one inch in diameter. Hornady now publishes “200 yard” Mach 2. book, “Applied Ballistics for Long Range Shootin. The The G7 standard projectile more closely represents today’s boat tail bullets and assigns them a more realistic BC than does the G1. The Spitzer is a very For example, a bullet with a ballistic coefficient of 0. The branch In other words, the drag of a modern long range bullet changes differently than the G1 standard projectile, so the coefficient relating the two (the ballistic coefficient) has to change with velocity. Convert a ballistic coefficient from one drag function to another. Comparing Advertised Ballistic Coefficients with Independent Measurements 2 Berger line Hornady now publishes “200 yard” Mach 2. 000 in) [0. As an example, a bullet can have a G7 BC of 0. 92 What is ballistic coefficient (BC)? For bullets the two most common standards are the G1 and G7 models, but pellets are so different that they have their own standard, the GA. 0] New Drag For slugs we use the G1 model. G1 vs. gives us a very small window of the projectile/bullet’s ability to overcome external factors such as wind and G1 projectiles are flat based bullets such as spritzer bullets, where G7 projectiles are going to cover boattail spitzers. The G1 shape looks like a flat-based bullet. BC = Ballistic Coefficient OAL = Overall Length Through an exclusive bonding process that eliminates voids in the bullet core, AccuBond® couples Nosler's proven copper-alloy jacket with its special lead-alloy core. Also, using the G1 model gives bigger ballistic coefficients, which look better in terms of marketing. Once these values are place into the BC equation G1 is 2x G7. 279 above 3000 fps, but when averaged from 3000 fps to 1500 fps, the G7 BC is 0. Drag Function: G1 Ballistic Coefficient: 0. The BC Changes with velocity and where we In ballistics, the ballistic coefficient (BC, C b) of a body is a measure of its ability to overcome air resistance in flight. A Better Ballistic Coefficient For centuries now, science has been helping us gain a more accurate understanding of our world. G1 is most commonly used because it’s the old standard and the industry has not adapted to the more modern incarnations. 243 Bullet Weight: 55 gr Initial Velocity: 3132 fps Sight Height : 2. You’ve probably seen that G7 values are numerically lower than G1 values for the same bullet Long range shooters who understand that Ballistic Coefficients (BCs) This is a much bigger problem with G1 BC’s than G7, but there is always some velocity dependence involved in using BC’s. Drag Function: G1 Ballistic Coefficient: 1. 5] Caliber (0. G7 Ballistic Coefficients — Which Is Right for You? G1 and G7 refer both refer to aerodynamic drag models based on particular “standard projectile” shapes. As Hornady moves the Ballistic Coefficients are measures of objects’ abilities to overcome air resistance mid-flight. We are working on a massive list, but this list won't be ready for a few weeks or months. 000) [0. Some more explanation about the transient nature of a projectile's G1 BC during flight can be found at the external ballistics article. fm ca nr ys hp pu gh ff zo br