I've owned quite a few crosman 1377/1322/2289s over the years. Just the one 1322 pistol now
Thrown a bit of money at it as happens with these guns. Its got a flat top piston, flat top valve with stock internals and a light hammer spring and new trigger internals, 2289 black grips and a silencer adaptor & a stubby light delrin silencer which does the job. The original 1322 had a hardened pivot pin which is great. I'm getting 5.2ish fpe with .22 hobbys (440-451fps) and what's great about the FT valve and piston is, that's after only 6 pumps (pump it any higher and power drops as hammer cannot dump the air). With the weaker hammer spring, there's air left in the valve and the second shot at the same power only requires a further 3 pumps.
There is a bit of hammer bounce so fitting a debounce device could help reduce the second charge number of pumps. But tbh, I'm not forking out for a HDD which is just a small bit of plastic shipped over from the states. It does all I need it for, is fun and a great little plinker/close range ratter.
Danny
My collection = Ratworks BSA Scorpion T-10 .177, HW100KS .177 (tweaked by me), PP750, Crosman 1322 and 1377