'BATTLE' rifle or 'ASSAULT' rifle?
While most of the world has gone to 5.56 NATO or 7.62X39 Russian, I'm a bit of a dinosaur, and prefer full powered 7.62 NATO in my military rifles. But I also like my rifles short.
These days I have M-14/M14S/M1a rifles. My current favorite is a shorty M14 I cut up, with a folding stock and a 19" barrel.
Back about a decade ago, I had original Dutch AI AR-10 rifles. I also cut up one of these into a shorty.
I'd be content with either an AR-10 or an M-14 as long as it was chopped into a shorty/carbine. The AR-10 handles better, and is more accurate as issued. The M-14 has readily available parts and a much stronger magazine.