Gun and mag problems

[digital_blue]

I recently bought a used WA colt. So far, Ive been running it on butane/duster the the mag seems to fill fine but for some annoying reason, theres like a sliding latch with a limiter screw that seems to be right under the gas release button. Now, every fillup, this sliding bar slips over the button and presses it down slightly so the valve is open every fillup and I get a crotch full of freezing gas. Any solution to this? Should I be using the recommended green gas? These are the only problems I have with the mag.

Now, as for the gun, after loading the mag in and cocking the gun, It will fire the first 6 rounds or so perfectly fine. After that, it will go into full auto for and it will release all the gas within less that a second. Isn't a mag full of gas suppose to last longer than a single mag? Secondly, could it be because I am using butane/Duster gas? I've already disassembled the whole thing and cleaned and oiled the thing but it still "slamfires".

any help would be appriciated.

[ThunderCactus]

there IS a solution, point the mag away from your crotch when filling it with gas