Today I'm taking an original (made in 1918) Artillery Luger rig out to a 6-stage USPSA match. I'm entered in PCC (pistol-caliber carbine) division using the detachable shoulder stock (note that this is exempted from the NFA, so it does not need to be registered) and the snail drum magazine. Happily, the ensemble ran virtually flawlessly through the whole match! Even better, I actually did reasonably well - certainly better than I had been expecting.