So recently I've started to get some failures in my Z5RS, which ran flawlessly for its first 2k rounds or so. However, I've had a couple failures to feed (round is just kind popped between the bolt and the barrel/chamber area, usually straight up or sideways) but always from the 2nd to last round in a mag.
It happens with 115gr WWB, 115gr Remington, and even 124gr NATO spec Winchester
First it happened with a 1981 date coded HK mag, and continued to do so even after swapping the mag spring to a new HK one as well. The feed lips are all fine and compare identically to other mags that function 100%, but I figured I'd chalk it up to a bad mag and drive on.
But this failure also happened with one of my MKE mags that came with the gun now too, albeit with far less regularity than the older HK mag.
I'm just kind of wondering if this is an issue that others have encountered, and if so, what the culprit is/may be?
When that occurs in the last one or two rounds, it is usually related to the magazine not being properly seated in the mag well or a weak mag spring that cannot keep you with the speed of the bolt group going into action. Try a different magazine.
If the problem continues, give Zenith a call. The guys in the armory will get you sorted.
Heckler and Koch Certified Armorer (Heckler and Koch) Heckler and Koch Pistol, Submachine Gun and Rifle Instructor (Singleton International)
That was kind of my first thought as well, glad to see I'm not off the mark here. I wouldn't think it to be the guns fault or you'd see it with every mag I own. I may try wolff springs, since the pressure is discernibly lighter to the touch than some of the other mags, even with the new HK springs I put in.