12-06-2011, 07:24 AM
mechanicuss Wrote:newbie reply here.
I have one of the JP A2's and it is a nicely machined piece. 2 cons though: 1. it has no provision for a sling swivel, and 2. it fits so close to the barrel that you cannot use a Colt M4-type side sling adapter (major bummer - are you listening JP?).
JP knows that their adjustable gas block sight towers will be installed on free-floated guns, so attaching a sling swivel of any type to it would be counter-productive, and their handguards are where everyone mounts their sling swivels anyway.
Mounting the sling to the barrel via a side sling adaptor (which comes from the M203 originally) has resulted in several catastrophic failures with M4A1's in high-volume courses that SF runs, since dynamic tension is applied to the gun with the sling, torquing the barrel to the left so that it starts to warp the receiver extension where the barrel extension slides into, which in-turn creates a situation where the bolt lugs unevenly distribute pressure with the barrel extension, and the guns let go into fragments even, with a guy holding a lower in one hand, and a vertical foregrip in the other, with a sling hanging around him.