Ok I just got done installing the Magpul ASAP sling attachment on my Bushmaster M4A3 Patrolman's Carbine.
Easy as pie.
Well after I was done I was reading on the net that the Bushmaster M4A3 has a commercial buffer tube and not mil spec.
Ok,so according to the Magpul A.S.A.P. installation instructions it says to use the longer locking key provided not the short key for the commercial buffer tube.
Long key = commercial buffer tube & short key = mil spec buffer tube
Well I used the short key,no way in hell that longer key will fit with my buffer tube.The short key works perfect,locks her up from spinning like its supposed to do.
So wtf is going on here?
Im irritated because I installed it perfect the first time without scratching up the castle nut.Then got to reading and was like well damn maybe I better try the longer locking key again just to make sure.Nope that suka ain't going in and the shorter key just popped right in like its supposed to again.Well the 2nd go around i scratched up the castle nut with the spanner wrench.Damn!
if it fits flush, let it be. I've had to "adjust" (file) those pins before. Sometimes the buffer is poorly machined, sometimes the key is poorly machined. Given the brands you're talking about... neither should be, but who knows. If the pin for the commercial tube fits flush and doesn't have any play in it, i'd let it be.