A while back I campaigned an XP-100 in .223 Rem for IHMSA Half Scale with a scope. I used two loads. The light load was pushing 52 grain bullets at a muzzle velocity of less than 2100 FPS and was used on Chickens and Pigs (not a very accurate load, but good enough for the distances). The fast load gave the same projectile a muzzle velocity of 2700 FPS, which slowed to 2100 FPS terminal velocity at the turkeys, and never left a ram (very accurate load). I kept the loads separated by the use of brass and nickel cases.