OK guys here's a question for you all. Curious to see what y'all think. Some years ago while shooting on the plains of eastern Colorado with some friends we were shooting a 3/8 in. thick steel plate about a foot square. I was shooting my Match H-bar, 20 in. barrel, 1/7 twist and my friend was shooting his mini-14 also in .223. We were both shooting from the same can of 55gr. FMJ surplus ammo. At about 50 yrds. my AR was going through the plate like a paper punch through paper. His mini -14 was denting the plate but bouncing off. What gives? Twist rate? Gas system? Shorter barrel? What do you guys think?