Excellent post! Great Job! Strictly speaking, this is at the muzzle, but measuring the actual scope with a ruler should be close enough. If you click one of these links before you buy, we get a small commission while you pay nothing extra. I really appreciate that, and Im glad you found it useful! My charts arent showing you what happens at across the room distances. Keep in mind this is an approximation and although it is quite accurate it should never replace first-hand experience of shooting your specific firearm and ammunition to determine the bullet drop and windage at different ranges and conditions. Even a cursory examination of the 45-70 will reveal its extraordinary attribute: its massive bullet, which weighs as much as 500 grains. This site and its community are a labor of love. Its a good zero, all things considered. Sierra includes a section in their Reloading Manual that gives a good, but basic, introduction to some of the concepts of exterior ballistics. A 14.5" barrel would give you much less velocity than a 20" barrel, hence the problems with lethality in M855 ammo and subsequent development of the 6.8 SPC Barrel length and twist should be factored in using your muzzle velocity - Which also includes things like your actual barrel diameter. Since the AR-15 rifle is such a highly customizable gun, there are various features you can change which impact muzzle velocity, and well examine them below. If I had to have only one book on the subject, this would be it. If we had an infinitely long barrel then there would be an equilibrium point. cartridge. At each range, handloads were used to seek out advantages given . [CDATA[ Sure, they are pretty close, especially with a 20 barrel, but do not think that because you zeroed at 50 yards it also means youre dead on for 200. Mark the rod, and measure the distance from the mark to the end. Please let me know how it can be improved upon. Learning Your Dead-Hold BDC Reticle Video. Velocity is affected by many different features working in tandem. When you look back over the history of the AR-15, youll find that we didnt just end up with a 55gr .22 bullet fired through a 20 barrel. First off, any rifle with a stock needs to have a barrel length of 16 inches or more, and an overall length of 26 inches or more (with the stock extended). With increased sight over bore heights, the interplay between target size and near/far MPBR force you to make compromises. Firstly, barrel length impacts a bullet's velocity. I will mostly be shooting for fun but also plan to use for home defense, apocalypse and zombie situations. Bison Ballistics Munitions, LLC Or when your neck no longer allows you to push your face down to the buttstock, and you resort to optic risers. calibers/cartridges. The app allows the shooter to select from a large library of bullets. I ran the numbers through JBM Ballistics and created these curves. The good news is that the cost of a smartphone-based ballistic calculator ranges from free to $29.99. And after further investigation, I realized that it was indeed an error in data selection for the charts. In most states, the shortest allowed barrel is 16. This calculator is used to find the optimal twist rate for your bullet. All Rights Reserved. Our calculator creates a proper ballistics trajectory chart that details range, drop, velocity, energy (fps), wind drift, and time. The modifications permit estimates for less than nominal full loads and using effectively any powder. CPRN: CCI 32 gr. It sounds like from reading this it may be better to set the 45 degree to zero @ 50 yards and the variable zero at 200 yards. Longer barrels usually mean more velocity. They all show nice tight little clusters from zero to 200 yards right in center mass. http://www.trijicon.com/mildot/mil-dot.cfm. For this article, were focusing on the physical forces propelling a projectile down the bore of the rifle. It varies depending on all the features mentioned in this article. Cartridges Abbreviated By Manufacturer: (C) = CCI; (H) =Hornady; (R) = Remington; (W) = Winchester CPHP: CCI 29 gr. perform. Picking a solid point-blank zero to minimize the amount of holding over you need to do is important, but you also need to be aware of where your impacts will fall. It sounds like from reading this it may be better to set the 45 degree to zero @ 50 yards and the variable zero at 200 yards. From them, the 6.5 Grendel 16 size may be the best choice for this scope. A longer barrel often provides more time for a bullet to generate velocity, as it is powered through the barrel by pressurized gas. Id have to go back to look at the chart, but theres a good chance that its user error in the spreadsheet that I made. HVTCHP Yellow Jacket: Remington 36 gr. Thats still useful, though, when you think about it. //