Just for giggles, try Remington 130 grain Core-Locts. They're not expensive, but should group around 1 1/4" in a decent rifle.
I assume you've tightened stock screws, scope mount and base screws and that you're shooting off a very stable front and rear benchrest setup, not over a rolled blanket on a pickup hood.
If the Core-Locts don't shoot as well as you'd like, try loosening the stock screws and holding the forend with one hand and barrel with the other move the barrel side to side and lift it slightly and do it again. If the action moves in the stock, it may need glass bedding. To see if bedding will help, you can put a couple of layers of electrical tape on the sides of the action at about 4 and 8 o'clock (analog) and see if it fits tighter. If it does, tighten it down, take it out to the range and shoot it. If it shoots better, consider glass and pillar bedding and free-floating the barrel.