Nope. I got the same result as you, it cycling fine for a bunch of mags, he gets it back and it screws up on him. Never saw it since I gave it back to him.

Pretty typical, guns seem to be afraid of me. Not the first time either that I've shot a dozen or so mags out of a gun I just ripped the guts out of, then put back together, and not a single issue. Owner gets it back, within half a mag something in the gun decides to fuck around and cause problems. Lol, at least with Shagg's M4 I found the gooves on the side of the Guarder FTK piston were a little too tight for the rail on the Hurricane mechbox, so I fixed that problem.

As far as those G&G slides................ crap, and feel like it too. I still haven't been able to get my G&G threaded outer barrel to work in my metal slide (no idea the make, but it's a milled block of aluminum), jams every shot, but the G&G barrel works just fine with the stock plastic slide. Bastard!!! :banghead: