Remember when Sig Sauer tried to market the MPX Carbine with a short barrel but fixed muzzle brake?

Yeah that didn’t fly with the ATF. Well I accidentally made my own. I was at the range comparing my Osprey 45 uppressed MPX against my friend Ian’s integrally suppressed AR-9.

That is a whole lot of can under there.

Both guns were shooting the same subsonic hand loads and sounded equally quiet. Ian’s AR-9 is not a traditional integrally suppressed gun, it does not have a ported barrel. It is a short barrel with a long suppressor welded onto the end. He wanted a single stamp gun.

I wanted to change out the piston in my Osprey to test another gun. When I tried to unscrew the retaining ring, I ended up unscrewing the blast chamber from the monocore baffle.

Silver lining is that I can clean my monocore baffle.

So I reassembled the Osprey45 but left the tube out and made a giant muzzle brake which you saw in the top photo.

I was able to reassemble the Osprey45 and used WD-40 to help remove the retaining ring and piston.