Not intended to increase gas for subsonic ammo-per instructions - KNS Precision Adjustable Gas Piston System

I should have read the instructions first. I was hoping to get subsonic ammo to cycle in my Ak47 (WASR-10), by increasing the gas flow to the recoil system. The instruction state that this piston is not intended to do that.
The instructions also mention that the original piston may be welded in place and be difficult to remove. Right again! It took me a couple of days and several broken drill bits to get the original piston out. I also destroyed the original piston in the process.
Having said all that, this piston can greatly reduce gas flow with or without a silencer installed.