Mach number is the velocity of the bullet divided by the speed of sound. I like the way you played it out, easy to understand for me as a new loader. Ballistic Coefficient of Hunting Bullets - The Old Deer Hunters In this comparison, the 6.5mm 144 gr bullet has a G7 BC of 0.336, while the 30 cal 175 grain OTM has a G7 BC of 0.263. When comparing BCs of different bullets, it is important to use an apples-to-apples approach. These are all pointed hollow point, boat tail bullets. Sign up to receive new product announcements, special offers, and the annual product catalog. In short, a high ballistic coefficient is indicative of a rounds ability to resist drag. ; G7 Ballistic Coefficient - this is an updated equation and the preferred system of measuring a BC for long range bullets. The slower the bullet the less range youll have. Or killing a deer with one shot. This means that the speed and energy will vary from cartridge manufacturer to manufacturer. The following is a 1000 yard .308 ballistic chart that was created using our free online ballistic calculator and details all aspects of the bullets trajectory from the millisecond it leaves the barrel until the time it reaches the 1,000 yd mark. You might see different BC numbers for bullets at different velocity ranges. Ballistic Coefficient values at Mach 1.75 (1954 fps @ ICAO Standard Atmosphere), should be used when calculating trajectories for shooting beyond 600 yds. In this comparison, the 6.5mm 144 gr bullet has a G7 BC of 0.336, while the 30 cal 175 grain OTM has a G7 BC of 0.263. Make sense? A bullets efficiency is measured by its ballistic coefficient (BC). If they have the same mass and velocity, the energy should be identical. It delivers smaller BCs but is consistent throughout the velocity of the round, giving you a much more accurate representation of BC. Its currently available in loaded ammunition and as a component for handloaders in .277, .284, and .308 calibers. It details drop, time, energy, velocity, range, and does so in . The B.C. (, We noticed that you have previously logged in with your, Check what do you get by creating an account, Bookmark and compare your favorite firearms, Ballistic Coefficient: Everything You Ever Wanted to Know, One of the first terms I ran across while discovering my fascination with long-range shooting was. Ballistic Coefficient - Hornady Manufacturing, Inc The password should contain at least 8 characters with at least one number or special character. AccuBond at 2600 fps. The extremely poor SD of the .224" bullet lowers its BC, even though its shape is similar to the others. As for distances, I'd already decided to choose 50 yards as the close mark, and after some discussion the editor settled on a max of 400 yards- a long shot, for sure, but a range at which most accomplished riflemen can make clean, ethical hits from field positions. A bullet with a high ballistic coefficient is slippery and less subject to drag (slowing down) as it continues on its merry way. Without getting into the math, I'll define the ballistic coefficient in words as: The ability of the bullet to maintain velocity, in comparison to a ' standard projectile '. If you look at the G1 bullet image, youll see that it resembles a common projectile shape from the 1800s era, give or take.