A powferfuls cope is handy for laod develpment ammo testing. But for that kinfd of rifle a 1.5 - 4X scope is about right, or a peep sight. I have a shotgun scope ( 2X ) on my 45-70.
If you shim the base, you need about 1 thou for every minute of adjustment. A piece of 20 thou shim stock should do the trick.