G35 Gen 4 - Round hanging in mags

[CFD43]

I'm hoping to shed some light on what may have caused the following malfunction to occur.

Background / Summary:

New G35 Gen 4. Gun had approximately 800 rounds through it without ANY malfunctions before this occurred. Only mods are, replaced stock sights with set of Dawson FO, 3.5# connector and competition spring kit (firing pin safety spring, firing pin spring, and trigger spring). Ammo being used was Federal factory, 180 gr FMJ. I had been shooting USPSA and mags were getting a little "dirty" (from being dropped in the dirt), but was functioning great. As routine, I disassembled each mag to blow out & wipe clean. Mags were left empty once cleaned - zero lube, just wiped clean. I had disassembled & cleaned several Glock mags before on my other guns without problems, not a new process to me.

What occurred:

A round would "hang" in the top of several different mags and not chamber causing the gun to go to slide lock. Racking of the slide would complete the chambering of the round and gun would function normally for the rest of the mag. Typically this was happening on one round per mag (varied which round in the mag), but a few times it did happen twice per mag. Shot about 200 rounds, and this occurred about 80% of the time. Again, varied on the specific round in the mag.

Got home and disassembled each mag and inspected thinking I was going to find something - found nothing obvious or unusual. I also disassembled and cleaned gun. Same thing, nothing obvious or unusual found. After mags were cleaned this time I loaded them to capacity and let them "set". When the above condition occurred, mags were left empty in range bag for several days.

Next day, I again returned to the range. Same factory ammo, but new box. This time I was equipped with camera, note book etc. thinking condition would occur again and I could document situation being I was unable to find anything obvious through dis-assembly and inspection. Gun ran flawless. Even tried to cause malfunction by shooting with weak / loose grip. I was unable to recreate situation at all.

Only thing I can think of that I done differently is I left the mags loaded to capacity. Before, I had left the mags set empty in range bag.

Thoughts ?

Many thanks ......

[MrVvrroomm]

I'd be willing to bet it's your slide stop lever. You're probably missing the end of the wire spring. It's very subtle, but causes exactly the malfunction you're describing. Odd though, that you're having this problem at only 800 rounds. Mine has thousands of round through it.

I was sure it was a mag problem. It wasn't.

I had this happen to my Gen4 35 at the Area 3 match this year.

[CFD43]

Thanks MRV -

Yeah, I'm trying to avoid the proverbial "ah crap" moment during an upcoming match also ... these things have a way of raising their head at just the wrong moment.

I did give the slide stop and spring assembly a close look when I took the gun apart looking for answers. The end of the spring was long enough to tuck under the top pin nicely and snapped back down on the frame without any trace of binding or being bent when pinched upward.

Being you mentioned this is a subtle condition, I'm not sure if I'm missing something other than ensuring it was long enough to protrude past the top pin so there was ample tension on the slide stop to keep it down and in place while shooting ? If I'm missing something please school me up.

Thanks for the suggestion - like I said in the OP, the gun seems to be running fine now, but without finding something definitive, that thought is always in back of my mind that it's going to happen again.

I did notice that some (not all) of the ejected brass had a slight scrap mark on the mouth of the casing as well as a slight flat spot on the circumference (also at the scrape point). The position looked as if it could have been caused by it slighting catching on the lip of the mag as it fed upward into the barrel feed ramp, but I could not make sense of the flat spot. Cause ? Normal ? Possibility Related ?

Thanks again ....

Edited September 11, 2012 by CFD43