Have you tried that out yet 451? I've always wanted to sbr one, but the price of .308 always talks me out of it.Got the rail for the PTR and the dang screws won't fit. Rail came with 6-40 screws...makes sense, very common but the handguard from PTR is threaded 5-40. What soulless engineer would use an oddball 5-40 screw? All I have is 5-40 1 inch, I either have to cut some down or hit the hardware store.