MFG# WEAVER 49721: WEAVER SEE THRU MOUNTS FN SERIES; Receiver Ring about 1.410" Diameter (98FN) I got this product to put on a 98 Mauser with a barrel that has iron sights. The Mauser is being sporterized for deer hunting. As with many parts used in a Mauser project gun, there was some fitting that had to be done. When I mounted the rings to the receiver, the ring saddles did not line up (the front ring was lower than the rear ring). This would have put stress on the scope, and could have bent the scope tube. I will explain how to easily correct this. I installed the rear scope ring to the receiver and installed some short pieces of plastic tubing into the threaded holes in the receiver for the front ring. I applied mold release compound to the front of the receiver (where the scope ring mounts). I then installed the front scope ring to a 1” piece of steel bar stock (scope ring lapping bar). I applied some Devcon (compound similar to JB weld) to the bottom of the front scope ring (the bottom of the scope ring was bead blasted to assist in Devcon adhesion). The front scope ring mounting holes was lined up and lowered over the pieces of plastic tubing and the 1” steel bar was set in the rear scope ring saddle and the cap was installed to hold the bar into place. This allowed for complete alignment between the front and rear scope rings. After the Devcon had cured, I removed the ring and filed off the excess Devcon that had squeezed out around the mounting area and cleaned off the mold release compound. I had to use some longer screws for the front ring as it now sets higher on the receiver. I now have an inexpensive set of see-thru rings that are a perfect fit for my rifle. One other way of doing this would be to grind or file off some of the base on the rear ring and bed the rear ring to the receiver. This would prevent having to find some new/longer mounting screws. You would have to be careful in removing material from the ring as to not remove too much and keeping the amount of material even across the base of the ring. Hope this helps someone :)