My neighbor gave me his ASG Dan Wesson revolver that was leaking. He had left a CO2 cartridge in it for years, so I thought it was the seal where the CO2 cartridge is pierced. I tried all the fixes and none worked. Finally ordered a reseal kit from PyramydAir for $8 and while replacing all the seals, I noticed that the O-ring inside the valve (see photo) was missing. Once that O-ring was replaced and all put back together, the gun is holding air. Yeah!!!
I'm glad I could fix it cause the Dan Wesson revolver is a beautiful replica.
