Piston Head O-Ring, Compression Issue

This afternoon I chrono'd my KWA SR-10 as it had recently been shooting visibly slow. The chrono showed my SR-10 to be shooting at 230 FPS.

I took the gun apart and felt a compression issue with the piston and the cylinder. Basically I placed my finger over the cylinder head port and moved the piston forward. You should feel substantial resistance doing this, and mine moved with ease. This told me that I had a compression issue in the cylinder.

My first thought was that this was related to the piston head o-ring. I was right.

I wanted to let you all know that you can purchase a compatible o-ring for the piston head at Home Depot (or other hardware store.) Get the 3/4" ring.

I put the 3/4" ring on the piston head and there was immediate resistance moving the piston forward with the cylinder head blocked.

I reassembled the gun and it now chrono's at 405 FPS.

Wow, that is amazing Chris! Glad you go it working well.

KWA BABY!