Tango- 7.62x39- AKs and 5.56- M-16 may have consequently killed lots of humans but they were designed to WOUND. When you have wounded you tie up all sorts of numbers of people recoverng, giving 1st aid, transporting to the rear, staffing field hospitals and such.

Wounding is one of the primary goals in battle because it saps the enemy's resources both human and material. The act of retrieving of wounded provides the enemy yet another opportunity to engange you on a disproportionate basis while you're distracted with the guys down.

It's the prime reason we have full metal jacket ball ammo. In any caliber in any army it seeks to accomplish the same task, to wound. An M-1 in .30-06 or a Mauser K98 in 7.92 mm in WW II would put a clean hole through your enemy's shoulder causing blood loss but not death. And we're back to wounded individuals drawing upon resources again.

5.56x45mm (.223 cal) or 7.62x39mm are not good large game rounds where the object is to stop with one shot. It doesn't mean they can't in the right circumstances but they do not have a proven history of repeatedly doing so. You don't want to wound a large animal an have to trek after it for what may end up being many miles and then attempt to haul it out.= if you find it befre dark at all.

Remember you can only load 5 rounds in most locales for large game so there's no spraying and praying. .223 and AK short rounds is what I'd say use for prarie dogs, racoons, bobcats, coyotes. For deer, elk, bear and other big stuff I'd use a full size cartridge behind a .30 caliber or 8mm Mauser round. For regions like some of the wide open Western states a hyperfast 7mm would be better for longer shots at elk.

Again to get back on track, it depends of what and where you're hunting. Brush guns and their game- boars, deer- require heavy slow projectiles that are not diverted by small branches and twigs like very fast rounds are. If you have ever really been in heavily wooded and thick brush area you know that you may not even get a look at the whole of your target and have to fire with partial view, past a dozen trees and bushes to hit what's back there.

Old Marlins, Winchesters, Savages and similar 30-30 "cowboy" lever actions are fine brush guns.

While 5.56 and 7.62x39 or any light, fast round fired singly will have dubious percentages of success they do the job when fired in volleys in full auto at military targets. Don't expect the kill of an animal with one round if it takes several to mow down vegetation and ultimately kill a man in the same terrain.

Literally any rifle with any mechanism with a full case size around .30 cal. will make hits in more open terrain at decent ranges. Only if you have money to burn do you want to get an African caliber firearm.