Another feeding issue

[Shaolin]

Hi All,

I have a M4 CQB-R. Its been fine for ages. Had a gearbox upgrade 2 months ago but gearbox isn't the issue as thats firing fine.

Basically I was out this last weekend and 1st half of the day was fine. Firing on semi and full auto, then the gun just decided to stop feeding.
Changed mags as I figured I must be out but when putting a fresh mag in, nothing. So changed to another mag, same thing.
I use Magpul PMAG's and they are all fine. They all release fine etc.
If I put a mag in, it will fire the 1st BB and thats it. I have a Guarder hop and hop rubber which are both fine. I've tried 3 dif hop ups and they all do the same thing so rule that out I think.
Only thing I can think of is that I started using a Metal Hi-Cap Flash Mag that day and all i can think of is that the metal Mag has grinded down the guides inside the Magwell causing an issue. Thats all I can think of as before I used this Flash mag I never had an issue.

Just as an experiment I took the upper reciever off and took the barrell out. I then put the barrell on the end of the Gearbox and inserted a Mag as it would be if the upper reciever was on. The Mag released the BB's into the hop chamber and there was no issue when I aligned it manually. When the upper reciever is on theres a issue...

Any ideas people?

[kurt458]

Re: Another feeding issue

have you got any pictures as i can kinda view it in my mind but cant work it out

[North West Outpost]

Re: Another feeding issue

Put your old hop up back in and see if they feed again, if so you are right to think you damaged your feed tube somehow. OR possibly the little locking mech in front of the trigger. So it doesn't hold the mags quite as high.

[Shaolin]

I changed my original hop unit back and nothing dif.
I've got a spare mag release catch lying around, I'll give that a go.
Even if I hold the mag in it still doesn't feed so not sure that would be the answer, I'll try it all the same, you never know.

What did u want a pic of??

[North West Outpost]

Re: Another feeding issue

I don't think I read that properly. So after using the flash mag your Pmags dont work.

BUT if you hold it all together outside the upper reciever everything is ok again.

It apears you have movement in the upper reciever, is the hop up loose in the upper reciever. Can it move up and down. It seems as if the mags dont go high enough cant be the feed tube worn or the Pmags would work with the other hop ups.

Anything stopping the mags going up into the mag well? A wire or something getting in the way.

[Shaolin]

Re: Another feeding issue

Nope, checked it all.
The Hop Up is nicely seated. There is no play baring the usual movement it needs, the mag well is clear of everything. Its rear wired so no wires.
I found that if I hold the bottom of the mag and pull it towards me then it feeds. I think it's mag well damage... All I can think of.

[TbirdX]

Re: Another feeding issue

Try a shim, a small piece of card or paper inbetween the gearbox and hop unit, you won't need much.