Mk18 Shenanigans

[457OnlyGovtITrust]

I have a DD Mk18 upper, LMT lower Fail Zero Bolt, radian raptor SD charging handle. When I cycle the rifle dry it is smooth as glass, when a round is in battery it requires super human hulk strength to cycle the rifle manually. Any ideas about what is causing this?

 

[cmshoot]

When there's no round in the chamber it cycles smoothly and easily, but very difficult to cycle when there is an unfired round in the chamber?

 

[jeep78]

Tight chamber or reloads.

 

[457OnlyGovtITrust]

I heard Honig the chamber with a chamber brush could reduce machining burrs. Hopefully that will help. The failzero bolt firing pin retention cotter pin was bent also at a strange angle that was keeping the bolt from freely moving in the bcg, that I think could also prevent the bolt from unlocking In the chamber

 

[457OnlyGovtITrust]

When there's no round in the chamber it cycles smoothly and easily, but very difficult to cycle when there is an unfired round in the chamber?

That’s correct sir