MD and Stick are right.
When shooting factory, I'd expect no better or worse than in a conventional chambering. Gun might like, or might not, and that's probably the bullet.
Normally, however, an AI or other wildcat is for handloaders who find factory lacking.
I did some 223 AI for a friend, handload from the start. As long as the brass was snug in the chamber (and this was a well-done 700 custom, so it was except for some virgin Rem cases, those I expanded and false=shouldered to "snug") the rifle shot. First I picked an FF load for him, and after he'd shot through enough of his brass, did fireform loads with NS only. Can't remember exactly, but the final loads were around 1 to 1.2 grains more of the same powder, same seating length. My impression was that groups were around a tenth smaller, with the FF's in the low .400s up to .5, but almost every group was a good group, nothing over .6
The Rem brass ended up fine, with the shouldering trick the FF's shot well enough to PD, and the final load result was much the same as the other headstamps. He loves that rifle. Still uses those loads, only change is he's seating them longer as the rifling wears.
