I got this slide and a 10mm barrel to mount on a Rock Island 10mm. All the hard work was done! The barrel fit almost perfectly into the slide and locked up with a over the .050 minimum. The frame rails took some filing to work on the existing frame, but it went faster than expected. Really enjoyed getting a “Longslide” that i’ve wanted for a long time, and considering adding a 357 Sig, 6” barrel to go on this firearm.