MK9 mag problem

[Romadoc]

I have a six rounder that keeps failing to feed as well a occasionaly blowing out. The other 6 rounder works fine. Anyone else have a similar problem? My MK9 is an all matte stainless which has a much better trigger than my K9s. I guess it has the Elite trigger without the ectching on the dust cover.

[Michigun]

I know you said only one gives you trouble, but I'd check your mag catch & mag catch spring out.