What kind of shape is the bolt and sear in? Too much wear and the bolt maybe "sitting" too far forward. I'm assuming you have the sear rod properly
Today I was messing around with an x-valve I have and while doing so it developed a leak down the barrel. It went away when I held the trigger so I knew
As per the Buy/Sell/Trade Forum rules you have to post a price.
If you don't know you can ask in the, whats it worth Forum for an idea.