my .223 AI rifles have 1-8" twist (22.5" Brux) and 1-7" (22" Hart). my interests lie more with getting 2850-2950 fps with the 75 grain A-Max. easy enough to do in my AO, but this gets me to 1K at mach 1.125 and 34 moa.
dont' get me wrong, the fast twist and the 55 grain V-Max (case forming load) shoots MOA at 500 meters, and the fast twist aids in making varmint confetti, but hinders velocity somewhat. i let the rifle tell me where maximum is, and i work with that. if that is less than some others get, so be it. the LRF has reduced the need for max velocity IMO.
