Jman

Has anyone successfully mounted a SIR type Rail ???

Stoked!!! Some really good info here! :thumb: I knew this was a good group on this forum. Thank you all for your ideas & advice. I was actually considering Trying Moly Powder mixed w/ Lucas HD Stabalizer on the bolt! Just for fun LOL

I think you might be on to something ... 2K rounds is a lot with no failures! What if the OEM bumper dimensions are responsible for a lot of the failures related to this Gun. And your damaged Bumper gave you good sucess that few have found ? ???

How cold is too cold for the Umarex M4 to shoot reliably? Went out yesterday in 25F weather, bolt was getting stuck back and creeping forward, Numerous Failures of every kind! Shooting Aguila Interceptors???