However right now my 'main line' rifle is a Yugo M48, 8mm Mauser (Which is really a licensed German 98k Mauser).
The ballistics are fairly close to the .308 (maybe a tad slower) and if my math is right the 8mm (7.92) works out to .31 caliber. But in any case, a .30 caliber is mandatory as far as I'm concerned for 'serious' shooting.
I almost feel sorry for those who spend all that dough on an AR-15 and clones with that wimpy .223 Remington. Heck I'd take an AK or SKS with the 7.62x39 over that any day.
I also have a 9mm Carbine - or as DiFi would say, an Assault Rifle. I bought that for, ahem, 'close in work'. It's good to 100-125 yards. And being 9mm it's the same as my 'main' sidearm so ammo is no problem.
And for my nightstand I have a 9mm Makarov (9x18) loaded with Hi-Vel 95gr JHP Cor-Bon's. This gun was once property of the East German Ministerium für Staatssicherheit (Stasi).
Anyway, I'm pretty well set - for now. But there are about four guns still on my 'wish list'. Isn't there always :-)
I like my AR-15 and have fired M-16's. If you care about quick mag changes and accuracy you might want to review your thinking. I don't think that I would have any trouble taking anyone down with either.
For home protection I prefer my .40s&w backing up my Winchester 1300 pump gun belting out 00 buck.