What calibers can you get in a match-accurate semi-auto rifle?
My dad has the terrible, terrible job of (legally) shooting deer out of his bean fields on a weekly basis.
He doesn't really have a proper deer rifle, though, because in OH deer are only legally hunted with shotguns. He's been using his epically awesome early-model Ruger 6mm Remington to great effect on both groundhogs and deer out to 400+ yards. It's probably the perfect round for both groundhogs and deer. But now he wants a semi-auto, for target-rich environments.
I know you can get AR-10 style rifles in .308. Now, .308 will kill deer, but might not be the best universal round for groundhogs, especially since he likes to use light fragmenting bullets on groundhogs to reduce ricochet danger. Of course .223 will kill deer too at closer ranges but at 400+ yards it does not give satisfactory performance. In AR-style rifles it seems he's stuck between two calibers. I have heard about ".223 but with a bigger bullet" rounds chambered for AR-15s but I don't know about their ballistic performance. What he really needs is a 6mm remington (or similar) semi-auto.
I told him he might be able to find one of those old Browning semiautos in 6mm or .243 or something, so that he could use his current reloading equipment, but I don't know how accurate those are. He's spoiled with some very accurate bolt rifles, and I know an even 1.5MOA rifle will sit in the safe.