I have mine in a Sage EBR. Bought it a few years ago at TSE in Calgary. The instructions that come with it are pretty straight forward. The most difficult part is punching out the pin and removing the guide rod assembly, and then getting the new one lined up and screwed into place. (And removing the flash suppressor, so that it will all slide off) The Sage will fit either the 18.5" or the full length. The only other issue is that you need to no the popsicle stick (or other similar thickness) fix, because the stock does not keep the Norc guide rod pin from working it's way out. I used a small piece or black plastic epoxied into place. It's the same color as the stock and you don't even see it. I've never had an issue with it. I do know that this stock turned my M-305 into a consistant 1.5" at 100 meters. On a good day, if I do my part, it will keep 5 rounds in an inch at 100.