Picked up a Ruger SFAR today and wondered if anyone had any insight on the buffer spring it uses. Top spring in pic is out of another 556 AR and bottom is out of the SFAR. Pics with receivers will show the tube is a little longer on the SFAR with total length of a hair above a standard ar15 tube @ 7 3/4”. I want to run a silent capture spring in it but not sure if the OAL of the JP spring will fit on the .308 model. I have a 556 one and it’s about 3/4” short. Anybody running a .308 one give me the OAL of yours? Can’t find it online.