it would puff back from the breech seal at 1200 psi, and worked its way to start doing it at 1500. not fun to get crud in my eyes. i was going to try the barrel set back, but the allen socket screw was rounded out on the inside hex. it came that way. in trying to set barrel back, i got it to leak between the breech and res. talked to tim at mac1 and he will fix it up. will be sending after the first.
as far as accuracy with it, i posted some pics of targets i shot with it here. it would shoot several pellets into a single hole at 10 yards. the trigger was good and the stock was not bad, but displayed some crummy workmanship, ripples or waves along one side.
i like the gun itself. is a fun gun to shoot and was favorablee impressed with the accuracy and power it had. it will be great when tim finishes with it.
here's some targets, testing different pellets. john
5 shot groups