U.S. Army looking for a new rifle...

[ExciteBike66]

32. So you speak for all who "know what they are talking about"?

Which would include me, as a former infantryman?

Anyway, your blanket statement is incorrect: caliber is certainly not the only dimension when it comes to power. For instance, another factor is the amount of powder in the shell, which affects muzzle velocity. Velocity in turn affects the kinetic energy of the round. Also, it affects the accuracy, although that is not a big deal in most civilian shootings (not many Oswalds running around anymore).

Furthermore, one can physically carry more lower-caliber rounds, all else held equal (one of the reasons the military uses 5.56 in the first place). The ability to carry more round and have more rounds per a given magazine size is a factor in the "power" of a weapon to kill a lot of people quickly.