Originally Posted by CDN_Stalker

Oil. The M11 GBB is renowned for requiring frequent and strategic oilings.

Having quickly read your thread, I'll point out the mag suddenly emptying the propane. Take the gun apart and hold the lower receiver/grip in your hand. Look inside the grip at the upper rear, you'll see a little lever type do-dad. The 'hook' on the rear of the bolt hits that, shoves it forward to release a shot of gas. If that lever is sticky in it's movement, that causes the valve on the mag to be held down releasing all the gas. Get some oil on the hinge/axle the lever rides on, use your fingers to move it through it's full travel. That should fix it.