Tm M9 - Bb Feed Jam Issue (Pictures)

[paradoxum]

I don't know what caused this to start, but after firing 1 round after manually cocking the gun, it will now almost every time jam when trying to load a new BB. It seems to get stuck on the hopup ramp between that and the BB loader of the nozzle:

Mag removed, picture taken of where the BB is stuck.

Sorry for blurry picture but this is where the jam is.

The BBs I take out from the jam have an indent on them where the loading nozzle has scratched them during the jam.

I've taken the hopup apart to check the bucking and everything, all fine. I've taken the nozzle assembly apart twice now and can't see anything physically wrong with it. I compared it with the stock plastic nozzle, and noticed that the loading nub on the aluminium nozzle was thicker than the plastic one, so I used a small file to file it down to match, still jams.

The nozzle has quite a bit of play / jiggles up and down, which is the only thing I can imagine that could be causing this to happen, is this normal? I can't remember if it always did this, nor how I would even solve it.

I took a video of the play of the nozzle here, tell me if it looks right:

Thanks in advance anyone. Really annoyed that this just started happening for seemingly no reason at all.

 

[BigStew]

Have you tried different BBs? Either weight or brand could be a bad batch. Is there any sign of damage on the mag feed lips?

 

[paradoxum]

Have you tried different BBs? Either weight or brand could be a bad batch. Is there any sign of damage on the mag feed lips?

Same BBs I've fired in it for a few months now all from the same bottles, although I have different weights I've tried all was fine up until two days ago when this just started for seemingly no reason.

No damage on the mag feed lips - I've got 4 mags and it happens with all of them.

Is the nozzle supposed to have that much play? that's what I need to know.

 

[Guest]

Standard fault finding, put the original nozzle back in, if it works, nozzle is the problem, easy

 

[paradoxum]

Standard fault finding, put the original nozzle back in, if it works, nozzle is the problem, easy

Tried that. Also tried putting the old bucking back in the hop.

 

[Guest]

Tried that. Also tried putting the old bucking back in the hop.

then it can’t be that. Put it back to completely standard, including gas routers.

 

[paradoxum]

Old gas route mag seals.

I took a video, after the first shot BB jams every time between hopup lip and nozzle. I clear it, rack the slide, and now it's started jamming even then 75% of the time.

Also at the end of the video the magazine vents all its gas for some reason which is now another thing.

Here:

It even looks like sometimes it is trying to double-feed, because there will be a BB jammed and also one in the chamber, but not every time.

 

[Guest]

So is the gun completely standard now?

And your using the same gas you’ve always used?

And the mags and/or gun aren’t too hot or too cold?

 

[paradoxum]

So is the gun completely standard now?

And your using the same gas you’ve always used?

And the mags and/or gun aren’t too hot or too cold?

Aside from the hopup/inner and outer barrels everything else is stock, springs and all.

Using nuprol gas now. I've previously used the same green gas fine but switched to propane (but I've ran out of propane).

Edit: Seems to be not jamming now. No idea what change it was though. This is perplexing.

 

[Nick G]

Barrel / hop unit not sitting correctly perhaps ?

 

[TheFull9]

Changing barrels and hop can definitely alter where the feed ramp and chamber opening are sitting in relation to the feed lips on the magazine.

If you can get access to a phone with a slow-mo setting on the video recording (new-ish phones do this pretty well) that's the best way I've found of actually figuring out what's going on in cases related to feeding issues.