This may be a little late, but when I bought my rings I couldn't torque them down enough to keep things from sliding around. Also, I then couldn't take the barrel/receiver assembly off the frame as others on this forum have run into. I didn't want to file, nor did I want to use epoxy (if you can take them off after they've been expoxied, the job wasn't right to begin with and if you can't take them off, well, 'nough said!). The solution I came up with is to cut small spacers from a plastic magarine lid to use in between the ring and the receiver. For the back mount, carefully cut a small square hole with an exacto knife to go around that "thingamajigger" that fits in the dovetail. Not only do the rings hold fast (even when disassembing and cleaning the gun), but you're guaranteed to never have the rings scratch off any bluing (if your's is blued). Good luck.