Seeking Help / Recommendations for MWS GBBR Full Auto Gas Leak & Tech Repair UK

[SullivanTrEE]

Hi all, I’m having a persistent issue with my Guns Modify TM MWS GBBR — in full auto it leaks gas like crazy (almost “spraying out” from the nozzle area). I’ve contacted Guns Modify support already and they kindly sent me upgraded parts, which I installed into the nozzle and trigger box, and it did help for a while… but now the leaking/over-venting has come back.


I’ve tried everything I can think of at this point and am stuck. Does anyone have experience with this specific issue (full auto blow-off / gas venting)? Could it be a nozzle seal / NPAS issue / trigger timing / hammer/valve set problem? (I’m also open to parts advice.)


Additionally, I’m looking for a tech / workshop that can do MWS GBBR repair & diagnosis — preferably someone familiar with MWS systems.
Any recommendations, contact info, or personal experience is greatly appreciated!


Thanks in advance!

 

[woody_2231]

what mags are you using? Newer GM pmags have gas through put problems, and is more temperature sensitive than Stanag mags.

 

[SullivanTrEE]

what mags are you using? Newer GM pmags have gas through put problems, and is more temperature sensitive than Stanag mags.

Click to shrink...

I’m running Guns Modify PMAG V3s and also Angry Gun Lancer mags.
Sounds like I probably should grab a couple of Tokyo Marui STANAGs and test for comparison — especially if the newer GM PMAGs are more sensitive to gas throughput and temperature.


Thanks for the heads-up