Perfect for ruger 10/22 to m1 conversion's - Leapers UTG Sub-Compact Rear Sight for Shotguns, .22 Rifles

I'm writing this review to help "Kurt,from IN" & others in his situation - Because Optics Planet won't allow me to comment on other people's reviews.

Kurt, the Picatinny rail system was developed in the 1980's by the US military/NATO - check Wikipedia for more info. As you discovered, it is different in size than the Weaver/dove-tail mounts found on most 22LR rifles, even the newer models.

Fortunately, there are adapters available that mount to the Weaver/dove-tail base & have a Picatinny rail on top - heck of a lot easier than shims ;-)

Optics Planet has just such an adapter for only $7.95, search "Ncstar 3/8in Dovetail To Picatinny Rail Adapter Mount MAD38PS" UPC: 848754002310

Judging by the pix, it looks like a nice solid unit. I definitely like the design & would not hesitate to use it myself. Be sure to use loctite on the screws, but, ONLY use the low strength type so you can remove the base if need be.

Hope you find this review & give the NCstar adapter a try.