Tuning Impact fps glich

[Keyman62421]

Have Gen1 ( Annie ) .power plenum shooting 34g JSB @ 895. Have developed a drop to 875. In a string of 26 it will do it once every 6 rds. or so.

Reg is hums holding steady and recovering normally. Checked C3 bumper. Seems to be there but " imbedded" in hammer c5. Not floating on shaft. Gun is dirty and I'm going to clean her today. I hate to take her apart for fear of needing more orings Any further suggestions? Where can I get C3 bumpers for the PP model?

 

[Seeker]

You may need to change PP oring as yours can be damaged. More on that here: https://www.airgunnation.com/topic/fx-impact-mk2-slower-first-shot-no-reg-creep/

 

[bigHUN]

For my MK2 when I did the valve poppet from peek in same time I made a valve stop/hammer spacer as well. Also polished the long valve rod, and all the parts that slides along. About earlier this year I replaced the HS again and I could see a brass powder in the trigger sear assy, the old spring was shredding slowly the hammer weight beside a fact I polished the ends about two years ago.

This is a last year picture showing how much the black plastic bushing can collapse after some heavy use ...

 

[Seeker]

Wow. That's some wear. I tried peek instead of delrin in the hammer. However, it seemed to be too hard with limited vibration reduction capabilities. My next try will be PA6.