My Marlin 336 came drilled and tapped. In fact when I got it from my FIL after he passed he had a scope mounted on it. I found using Remington green box 150 gr 30-30 ammo, I could put the whole 20 rounds in a group about the size of a quarter at 100 yards. Good enough for hunting. Like already brought up used 336's are a dime a dozen. I've seen the BLR's get a little sticky to operate after firing a 308. Should br ok in 30-30 I would think.
God Bless our Troops especially our Snipers.