A lesson learned on an S-6.
Every now and again I play at a field which has some VERY fine talcum powder style dust.
If it gets into my bottom tube - I have hell to pay with my Series 6.
Here is what I (re)learned today. If you are getting drop off - or drop off in auto trigger - after you verify your regulator is recharging properly - check your hammer and bottom tube. Clean both and polish your hammer if you can.
You will likely solve this problem.
CCM's seem to have tighter tolerances in their bottom tube - so it might just effect CCM markers (or others with close tolerances). However, it seems like a reg problem and can drive you nuts if you keep going back to the reg while trouble shooting.