So my main gun is a pump mag, and this last weekend I was having some real problems with broken paint. It's a classic valve LVL 7 pump in a z body. I have a foamied Venturi ANS bolt in it. I was shooting Hell Survivors red marbz, and it was between 55 and 68 degrees while playing. Some of the things I tried to fix it:
- using a wider bore insert (went from 684 to 687 and then to 693)
- swapped out the foamie bolt for a non foamie venturi (the foamie is a little worn down)
- turned down the velocity
- switched to semi auto (removed wave spring and put in standard length main spring)
Aside from some double feeding issues from a sticky detention, I notice that I had no breaks once I switched to semi auto. This would indicate to me that my trimmed mainspring is not "restraining" the bolt enough when the gun is firing, resulting in breakage even in a semi cold day. The same set up with the same spring worked fine on a day in the low 80s in July (two days straight actually - Global Survivors).
Does anyone have thoughts to share, or critiques of my hypothesis regarding the shortened mainspring?