Hello fellas well I've had a little time to play and work on my PP750 now that I'm back home from vacationing in Yellowstone and trout fishing at Roaring River State Park before it closed and bowhunting, so here we go first up I bought this for shooting sparrows off the feeder so I don't need a lot of power so I left it setup for the Canadian power as shipped from West shooting the RWS dome 8.3gr Hi-444 Low-419 for a 10 shot string with the HST set flush turning it in did nothing and 4 sparrows down, decided to see what it would do by just changing out the valve body well it helped the fps RWS 8.3gr Hi-766 Low-719 for 15 shots HST also flush so I could actually get quite a few shots and still be ahead of the original valve, so next up I decided to open the the valve port on the original valve body only drilled it 1/16th inch using RWS 8.3gr I run 30 shots for a Hi-578 Low-532 more than enough power for pest birds and real quiet with Brian's 3D moderator. I also did the trigger mod by replacing the adjustment screw and the spring much better now, also added some notches on the buttstock rail for added adjustment and washers in the factory shroud to help make it quieter. Here's a couple pics of how she looks. 
