Ehhh,, at one time when the army was interested in killing the enemy the standard was 30-06 and .45acp. I imagine a carbine design with 30-06 as a round could be effective at the specified ranges and strangely enough they have a crap load of it in surplus inventory.
Yuo can’t go wrong with any of the Holy Trinity:
FN-FAL
M14
HK93
Honorable mention - M1 Garand.
I’m a FAL and Garand rifleman. Even at my age and condition, I can still shoot in the low to nid 240s on the AQT. Good enough to knock a blue helmet or a turban off an enemy head at 500 yards.
You basically made the .308 argument. 30-06 was a great round, but the .308 had similar ballistics, was smaller and lighter, and could be in a short bolt weapon. We have plenty of that round also. As for the .45, .........winner,..duh. If I had a 9mm in battle, it would probably do more damage if you threw the gun at them. If you just have to have a 9mm, go for the 357 Sig. Maybe it’s just me, but when my life is on the line, I want something that will go through car doors, house doors, a little armor, trees, bricks and so forth. The AK 47 has the ballistics of a 30-30 and it seems to be ok for every war in the world because the .30 cal bullet is heavy and you usually don’t shoot 100 yards. The .308 is just far superior for long ranges and penetration. M4 is a pop gun,IMHO. The M16 at least had a longer barrel and more speed. Cutting the barrel just takes any punch you may have and sacrifices it for compactness. If you are in a building, couldn’t you have your pistol out( if it is a .40 cal or above)? I don’t know, just random thoughts from a guy that loves to see bricks shatter and bark fly when he is shooting. .22’s are fun when your plinking, but I don’t consider soldiering, plinking.
The .30-06 was adopted when the ability to kill enemy cavalry mounts (i.e. horses) on the battlefield was a legitimate requirement.
I'm not taking anything away from the round or the weapons that fire it (IMHO, I think some type of BAR equivalent should be available at the squad level), but it's a little rough for a lot of female soldiers to shoot. That's just reality.