TM MP7 Mag - Knocker Valve

[C-Diddy]

Apologies if this has been asked before, but my search hasn't turned anything up.

Took my  gas TM MP7 to a skirmish yesterday and everything was going great. Went to the range to test some new ammo (.32 Open Blasters) and after putting a couple of mags through with no trouble, albeit not as good results as my usual .30s, after a couple of shots, the third mag vented all the gas. 

The gun is fine and continued to work well, but the knocker valve on the mag seems to be stuck in. The plastic piece is just kind slack.

Any ideas on how to fix it? Most disassembly videos remove the base plate, not the business end.

Help and advice appreciated. Abuse is extra but perhaps warranted. 

Edit: I should add I was using Zero One Pro Gas, which is similar to Abbey Predator Ultra gas

 

[Guest]

Sounds like it froze and jammed, does the mag have a cover, so take the base plate off and pull a thin steel cover off so you can get to the outlet valve?

 

[Mr. No_Face]

Can't offer much help on this front but the TM MP7 was something I'm actually considering getting. Are your mags gas, modded by any chance? 

I left my MWS with my local tech regarding the venting issue and they said modding the mags would reduce the likelihood of this happening among a number of other suggestions.

 

[C-Diddy]

Sounds like it froze and jammed, does the mag have a cover, so take the base plate off and pull a thin steel cover off so you can get to the outlet valve?

Thought it may be something like that as it was a freshly filled mag. I'll have a play

Can't offer much help on this front but the TM MP7 was something I'm actually considering getting. Are your mags gas, modded by any chance? 

I left my MWS with my local tech regarding the venting issue and they said modding the mags would reduce the likelihood of this happening among a number of other suggestions.

Mags are untouched as are my MWS mags.  

The MP7 itself is fantastic, so I'm not too disheartened. 

Be interesting to hear how your MWS gets on after modding the mags. What else was suggested out of interest?

 

[Mr. No_Face]

Thought it may be something like that as it was a freshly filled mag. I'll have a play

Mags are untouched as are my MWS mags.  

The MP7 itself is fantastic, so I'm not too disheartened. 

Be interesting to hear how your MWS gets on after modding the mags. What else was suggested out of interest?

Well the tech guys, stripped everything down and found nothing wrong. Everything was lubricated and functioning which narrowed it down to the mags. I've been following the instructions of "ollie talks airsoft" in regards to how to fill the stock TM magazines to get the most out of it. Well turns out Ollie's way isn't the most practical. 

When gas starts to spurt it's indicative of a full or over filled mag which increases the chances of venting. The simple answer is don't over fill them. Even more so when it pertains to using high pressured gas with the already limited capacity (stock) TM magazines. The techs also recommended that I adhere to the appropriate gas listings when using stock magazines that haven't been modded. 

With that said; all my mags are now modded.

EDIT: Oh and since the techs didn't have any decent nozzles in stock I am sadly stuck with the "angry gun" MPA nozzle.?

 

[C-Diddy]

That's interesting @Mr. No_Face I don't plan on modding my MWS mags but let us now how you get on.

I've seen a similar mod for the MP7 mags but, honestly, apart from yesterday's hiccup, I've not had an issue.

@rocketdogbert I'll post a pic or video when I take a look tomorrow, so you can see what the deal is. 

 

[C-Diddy]

@rocketdogbert this is what I'm facing:

View attachment 88539

my plan is to punch out the little pin highlighted, remove the flappy bit, then remove the valve, unless you think that's mental?

The mag just vents any gas you put in which would point to the knocker valve, as you said, being jammed.

 

[Guest]

@rocketdogbert this is what I'm facing:

View attachment 88539

my plan is to punch out the little pin highlighted, remove the flappy bit, then remove the valve, unless you think that's mental?

The mag just vents any gas you put in which would point to the knocker valve, as you said, being jammed.

looks about right, vents when you put gas in, or when you load the mag in the gun?

 

[C-Diddy]

looks about right, vents when you put gas in, or when you load the mag in the gun?

When I put gas in. I've just removed the valve and can see that the spring has ridden over the silver bullet bit. At least I know it's just a case of replacing that. Now to find a part that's in stock...View attachment 88540