True "Weaver" mounts probably work fine, 1913 Picatinny mounts do not. I discovered an Eotech wouldn't fit mine. Looked at milling the entire rail to the 1913 standard and refinishing, but the existing grooves don't line up perfectly. Then I thought about making an entirely new rail, but finally decided a 22A isn't worth that much of my time. Evidently S&W thinks the same thing or they would have updated the design to the Picatinny which would work with both.