Hey guys, does any one out there know anything about scope shimming? I was just messing with my MVP today, and realized my Vortex Viper only had 16 MOA of up elevation adjustment. I looked at the Burris signature rings, but I like the price of old pop cans a lot better. I think I would rather shim between the rear base and the rifle instead of the rings, is that a bad idea? Any advise would be much appreciated, thanks!