My brother is trying to validate his drop at distance using my reloads in his 7mm Rem Mag. He was consistently low (7 shots) 1 MOA at 600 yards. Given Nosler's tendency to overstate BC, how accurate is the published .531 for the 160 NAB?
http://www.dtic.mil/dtic/tr/fulltext/u2/a554683.pdfHow close to reality are the BC figures for the Hornady ELD-X, specifically 7mm 162 and 175 grain? I'm thinking about switching from the 160 NAB.
P
Using Hornady's 4-DOF calculator which they say is "based on projectile Drag Coefficient (not Ballistic Coefficient), combined with exact physical modeling of the projectile and its mass and aerodynamic properties." Also, I've read about Hornady using Doppler radar in the development of their ELD and ELD-X bullets, so I'll assume their calculator is as accurate as it gets for the few bullets they list.
Selecting the 7MM 162 EDL-X from their list of bullets and using standard atmosphere values with a 3030 fps mv I use the calculated velocity at 600 yards and entered that into Ballistic Explorer to find the G1 BC, which is 0.640 and the G7 BC, which is 0.319. Using those BC values in Ballistic Explorer the 600 yard velocity is within 1 fps and the "Come Up" from a 100 a yard zero is within 0.04 MOA between Hornady's 4-DOF calculator and Ballistic Explorer.
Hornady advertises a G1 BC of 0.631 and a G7 BC of 0.318. If you use 0.631 then the come up would be off by 0.1 MOA at 600 yards compared to Hornady's 4-DOF calculator. That's way more accurate than most guns, let alone, most shooters can shoot.
They don't offer a 7mm 175 grain ELD-X yet.
