I'm thinking valve spring in the light of the new day as well. I know that when it fires with no gas that it's really got a wussy hit on the valve pin. Unlike my direct CO2 Piranha blowbacks where the valve spring is a lot harder. Not to mention the super hard springs in the Nelsons.
I've got an autococker spring kit. I'll look into swapping the valve spring to a harder one as a first step. The hammer spring already seems fairly soft when cocking it so I'd almost prefer not to make it any weaker.
I had a "Paintball God" moment once.
Like Al Bundy's Polk High football moment I live on
for the slim chance of repeating that one time
miracle in some small way.........