We use the Piranha valve because it is a good valve and we had to keep the cost down on the gun to be able to release it. I don't often hear of them leaking but will look into that. I know that know we are blowing away all expectations of sales with the guns that some have come through with issues and the more guns, the higher that number is even if it's a small percentage.
I will bet that very few people buying Snipers take the valves out... sometimes we find that the more we put in a manual the more people that shouldn't mess with something screw it up... and those that do take the valve out would have the sense to work out how to fix it, just like you did.
If we ever get to redo the Sniper I'll get that added to the trouble shooting section.