I've said it on other threads, but my TM 1911's will empty a full mag minus one round with a single charge of propane in rapid fire. I've tried it several times and hammered out a mag as fast as I can and it always leaves one round in the chamber when the gas runs out. So, just put 25 rounds in the mag instead of 26 if you want the slide to lock back.
That being said, NEVER in a game have I emptied a full pistol mag in that fashion. Even in a pistols only game, no one ever fired more than a few shots in a row without a few seconds inbetween. For practical use, don't be shy with a 1911 if you think it's your style.. just avoid the WE's or be prepared to search ASC for all the fixes done to them.
Tpr. Spencer, DF
RCD C Sqn - CFB Gagetown
Please save for me, some gallantry
That will echo when I'm gone