for a long time i've been curious why different .223 ammo shoots so different in all guns. what shoots great in some, ain't so great in others-even with the exact same load. some barrels like lighter bullets, others heavy. so, i'm curious, for reloading .223, what are the critical things? obviously bullets, but after that, then, what? i've shot lots of different powders, and don't think that matters much. so, what's next? case prep? case length? OAL? crimp? we're not shooting benchrest in 3-gun, but what might be the most critical part of reloading for .223?