Trouble with AR pistol piston

splatacaster

I purchased a AR-15 10inch pistol with a gas piston. The problem is it fires but dose not eject the spent catridge. I took it apart all holes are clear, however, it being an older modle and not sure of the manufacturer, not sure if all parts are there. It seems to resemble the retro fit Bushmaster the most. I contacted Bushmaster and they said they never made a piston to fit a 10" barrel. So, it led me to think, that maybe the reason it may not be working is that it is the wrong size. I think it may be, because the bolt actually makes contact piston in bolt closed position. In trying to figure out what was going on I found that the when first loading the weapon releasing the bolt it was knocking the gas block forward and inturn interupting the gas flow by repositioning the gas port holes. Thus the fireing and no ejection. So, in an effort to try to slavage the money I spent without dropping more down, I guess the question is this: Is the the piston on retro fit piston systems supossed to come into contact witht he bolt when bolt is closed, basicly resting against each other? Is it possible to cut the piston down 1/8 to 1/4 inch so the bolt does not come into contact with the piston when returning to battery? Any sugestion???? Thanks

Mobuck

I'd say you found the problem with the overlength piston interferring with the bolt. Has the gas key been changed to the flat faced type meant for use with the piston? Those parts would be made of hard steel or hardened and cutting would very likely require rehardening of the piston. All that stuff is designed to work within certain parameters and cutting/lightening the piston might cause unforeseen issues with other parts. I don't mess with piston AR's, the original design is good enough for my needs.