pumpmag leaking when not cocked

[phizz]

I have a pump mag with a classic valve. The problem is that when the gun is not cocked and ready to fire it leaks. When you do pump it the leak stops. Also if you leave if for about 10 seconds it ends up cocking itself. Any ideas what to do?

[flyingpootang]

Phizz, it may be the bolt and/or sear. I think that the worn part(s) are allowing the sear to sit on the edge of the bolt. This is causing the on/off to partially open and to leak until the bolt is reset by the pressure of the on/off over coming the edge of the bolt. Pm me your address and I'll send you a L7 bolt & sear.

[athomas]

With a good wave spring installed, the pump mag should never be able to cock itself.

Also, to prevent the leak when not cocked, try a shorter powertube spacer. This will allow the powertube oring to sit farther forward against the bolt stem even though the bolt is not fully returned due to the wave spring.

[flyingpootang]

Phizz, I just sold another pumpmag and tried to install a wrong sized and nicked o-ring, both came up with the same situation your are having. Try it out and let me know. How did the sear and bolt work out. Help any????