Thread: .270 muzzle speed

BC changes with velociy so as a bullet slows the bc value drops. A single bc value will not apply at velocities outside the one it actually applies to. A bc value applied to say 3000fps will not apply at v 2300fps. Thus for field ballistics proof of poi at various ranges is best acieved ny actual tests at the ranges encountered in the field. Mv's quoted by manufacturers usually apply to test bbl lengths 24-30") which are often longer than shorter hunting bbls so max mv may not be achievable. So, a shotened bbl combined with low mv and lower bc means performance under design optimum for many cartridges and the actual ballistic curve will differ from optimum quoted by cartridge manufacturers. Verify by shooting.