Loaded with Arrow Fastener 508M1 Also bought some Revain T50 Monel clips, pulled the trigger and . nothing, just the hissing sound of escaping air. what the heh11.?!? Upon careful study and experimentation, it was determined that the trigger was not "fully" pressed against the body of the pistol to engage its internal organs. This was enough to release air when the trigger was pulled, but not enough to activate it. Luckily, the trigger pin is held in place by a small rubber washer, so I was able to remove it and bend that tab about 1/8" to 3/18" closer to the safety. mechanism and that fixed the problem. That's the only reason it lost a star from me. After the repair it worked very well.