Second question first - I'll get it re-barrelled so can have it twisted fast enough to work. On velocity, I was using 2700 ft/sec based on Hodgdon and Nosler data. I suspect I'd fall 25-50 feet short of that with a 22" barrel.
I get 2790 with the 150 (bc .574) and a max charge of Big Game. You might get 2650 with 162 (bc .630). At what distance do the bullets drop below 1800 FPS given the estimated muzzle velocities?
Hornady online ballistics calculator say 675 for the 150 and 650 for the 162. 2675 muzzle velocity gives you 675. It’s not sophisticated enough to calculate wind drift.
P
