OK, I must have had decaf this morning too because I didn't catch it either. LOL! But yeah, 1/4-28 would be a little small for the bolt screw wouldn't it.

I don't know which style of bolt it is. I haven't been into it yet. It came on an older 112 22-250 single shot. As hard as those screws are to shake loose I could see leaving some damage marks on them with a flat head screwdriver. I would rather change it to an allen head.