I wanted an AR stock on my PSL, so I cut off the tang and installed an ACE receiver block, with a pig nose that just bolts onto the adapter block into which the AR tube screws. It was OK, but I thought it felt a bit weak. Then I found the Iron Industries rear trunnion, which is set up for installing an AR buttstock. First I had to remove the rear trunnion rivets, then fit it to the PSL. My PSL has a square-back receiver from Nodak Spud, same as an AK. It also has holes for 3 rivets, for which I had to drill a third hole. My rivet set was way smaller in diameter than the holes in the trunnion, so I had to order some larger diameter rivets, which I got from Mcmaster-Carr. Believe me, this would have been easier if I'd found the Iron Industries trunnion first when I was building my receiver. Having that long barrel installed makes it harder to do a good job squeezing the rear rivets. its not as pretty as I'd like it but it works.