I just mounted a scope on my air rifle for the first time and it is shooting about 5 inches high at 15 yards.It only has about 1" of adjustment at that range. The one piece mounts came with the scope and the look like some of the one piece AR mounts like the Burris mounts for an AR. Very heavy duty. Eight cap screws for the ring caps and 3 large cap screws to hold the base on the receiver. Some of those AR mounts have built in elevation. I guess I could take it all apart and reverse the mount and see if it shoots low. This mount fits in the grooves of the receiver and will fit both 3/8 and 11mm grooves. It also has a stop pin that screws up and down into one of the two holes in my receiver. It looks like I will need to shim the scope higher in the front ring. Any suggestions for something to use for shims?

go to the auto parts store - they will have brass shim stock in various thickness.

Brass would be nice, but aluminum from a soft drink or beer can works too.

As shims to check headspace, I have cut up leaves from an old feeler gauge to put behind a cartridge. If they are flexible enough or could be located on each side of your mount, such steel would give you varying thicknesses and also might avoid the dangers of corrosion (electrolysis?) that could be increased by mixing metals. By having a different thickness on each side, you might even get a modicum of lateral adjustment without winding your scope adjustments out of centre.

Thanks to all of you for the advise. I had some metal tape used for taping metal HVAC duct work. It really worked well and I think I used 3 layers to correct 5 inches of elevation at 15 yards.