OP, like Plank mentioned, try a little of each, see what it likes. ARs are like snowflakes when it comes to steel-case, and some just flat-out don't like steel.
Cabela's "Herters" steel(re-boxed Tula), has run wonderfully in my PSA, Stag, RRA, and BCM rifles.
The carbines run H-buffers with the hotter quality ammo, I swap in a standard buffer when I'm going to blow steel at the range.
"I'll have a Coke..."