Hello Fella, I bought a whole bundle of these guns to run at my site for the public to use, however, and I don`t know why ? for these we use steely bottles, when we screwed the reg in, we found the Pin in the Regs either Bent or broke, ( basicly not aligning themselves together as we screwed it in ) of course if the Pin doesn`t align or partly connect, you wont get enough or any air, It`s a cheap throw away gun and if you use a cheap bottle, expect a few little Quarms, hope yours is of course ok !! but have a look just in case BEFORE you start messing about with the gun, :- Try another Bottle ??