07-08-2011, 01:34 PM
Take the 120 GMX shape, use voids up front to move the CG aft, different materials for improving penetration, etc., to reduce the weight to 100 gr and one gets a BC of .400 assuming the same shape factor.
This BC, coupled with a MV of around 2750 ft/sec for an 18.5" barrel (see http://ammoguide.com/?catid=456) and you track the 7.62X51 M80 fairly well for trajectory and wind resistance.
The bullet would have 90% of the sectional density of the M80, so would need some design effort (e. g., M855A1) to bring the barrier defeat and armor penetration up to the M80 level.
This BC, coupled with a MV of around 2750 ft/sec for an 18.5" barrel (see http://ammoguide.com/?catid=456) and you track the 7.62X51 M80 fairly well for trajectory and wind resistance.
The bullet would have 90% of the sectional density of the M80, so would need some design effort (e. g., M855A1) to bring the barrier defeat and armor penetration up to the M80 level.