Smith & Wesson M&P40 Springer Piston

thingiverse

The piston on this airsoft pistol has been a major problem for many people. It simply does not have the strength required to withhold the force put upon it. Because of this, I have designed a piston that airsoft hobbyists can use to repair the gun when it breaks, rather than throwing it away or buying a new one. My design uses a triangle support on the little square nub that the force is applied upon, and that seems to have solved the problem. I have shot about 200 plastic bb's through the gun with this print and am happy to say that it has not failed, nor has it shown any signs of weakness or rapid deterioration. Update 7/7/2018 - After shooting about 1000 shots through the gun with the new piston, I have been experiencing some seizing problems. The pistol's slide will freeze in place and when forced forward, will fire without the trigger being pulled. The gun also fires without the trigger being pulled if you cock it all the way back and let the slide spring forward. I am unsure if this is a problem that the gun has always had or if it is an issue with my upgrade. Please print and test this and provide some feedback so I can update my file if need be. I will continue experimenting and give you an update when I think I have fixed or changed something.