I have a used Olympic Arms upper chambered in .40 S&W. This upper has a 10 inch barrel that was built that way by OlyArms and isn't a cut down 16 inch. The muzzle has been threaded in .578x28 for use with a .45 suppressor piston. Works on blowback and comes with three original Olympic Arms magazines. These mags are converted Uzi mags and are exceedingly rare. The last time I saw mags like these sell online they went for over $100 each.

The BCG has is a full auto style and I know it works on full auto. Comes with the Magpul FDE foreend and also a thread protector for the muzzle.

I'm very firm at $800 shipped for this upper w/ mags. A 16 inch Oly Arms upper is $720 with only one cheap polymer mag. You can't buy shorter uppers so you'd have to pay to cut it down, recrown, and thread. Plus mags are $50 each new for the poly mags. This is a deal and I won't negotiate on price.

The only trades I'll take are an Aimpoint H-1 or T-1, Trijicon RMR with adjustable LED, or a Surefire X300 Ultra. Each one of those will need cash on top.

Thanks for looking. This is a one of a kind upper and I challenge you to find another like it.