.556

I was just thinking, isn't it weird that when comparing .556 and .45 ACP, even though the a 16" .556 has over 3x the power of a 5" .45 ACP (1174 vs 378 Ft/Lbs energy), that the .45 actually has more momentum. Not that that does or doesn't count for anything, but if comparing a 55 Gr .556 and 230...