>>2290711the meme comes from performance in Vietnam, where people were used to what was essentially fucking overkill rounds. Consider that .30-06 is used on big game, and that in WW2 that's pretty much what we gave standard issue with an M1 Garand. then we moved to .308, and then down to 5.56.
A lot of people thought we were sacrificing a lot of range and punch with such a smaller round, but the trade off was that the guns were much lighter, ammo was lighter, and it pierced armor pretty well anyway.
It also took a while to "perfect" the round for the twist rate and barrel length at the time, ie., things like M193 vs. M885 and all the other variants.
