FX Plenum size?

[Bearwhiskers]

I think I have too much plenum volume if that’s possible. My fx king was a .30 cal 600 mm slug gun and I converted it to 22 pellet. I tuned it way down and it shot well but I wonder if it could be better with a smaller plenum. I’m currently reg pressure at 75 and the hammed all the way down to 1 Any advice is appreciated

 

[MongooseV8]

What hammer weight do you have in the rifle? I bet your hammer strike is too heavy, the plenum size shouldnt really affect anything in a negative way.

 

[Bearwhiskers]

I have not changed the hammer so I don’t know but I suspect it is a heavy one