I purchased a used R10 a couple of months ago, it started leaking about 50 bar every time I took a shot emptying the block but not the air bottle. I resealed the gun, swapped out the valve which I had an extra and regulator. The gun had a Huma regulator, put the old regulator back in, it shot fine. So I resealed the Huma reg and everything was fine. Pulled the gun out this week and doing the same thing. Is it possible that the poppet valve is sticking? Thanks Rick