FPS Lower than expected... (Air seal issue?)

[GI Joe]

I'm happy it's not the gearbox which I worked so hard to get shimmed and sealed just right.  I'm still a bit worried that letting the spring push the hop up unit back against the feeding tube may cause damage to one of those two parts over time.  I'm going to play with it again tonight and see if I can't just modify the barrel assembly to give it a little more play without having the screws removed completely.  Damn irregular hop-up is near impossible to find short of buying another Masada... and I hear it takes some skilled modding to allow it to take normal M4 style hop-ups.

[Northern Lights]

That spring tension system is how that standard M4/16 hop up is secured. You should be good. I would bet it is a QC goof and the body mold is 0.25-0.5mm off and that gap is enough to allow air leakage. I would leave it and field test it then on Sunday make your next move.



Lights out

[Carrico]

Glade to hear that it worked- that was the same prob Dillion was have with his fn2000 after he changed the noozle

[GI Joe]

I would bet it is a QC goof and the body mold is 0.25-0.5mm off and that gap is enough to allow air leakage.

Maybe, but the gap wasn't there with the factory nozzle/gearbox.

Anyhow, get this.  I fiddled with the screws again, decided not to re-install them because I felt the way the hop-up and feeding tube mesh was fine.  So, I went ahead and put everything back together... damn thing is now consistently poor-man-chronoing under 385 again!!!  Not sure what I may have accidentally tweaked but now I'm back where I started.  I'll have some more time to mess with it before game, with any luck I will get it firing over 385 again.

[Northern Lights]

Every time you open it up you get something different. Sounds like you should roll the dice and open it up again. It sounds like something is loose. Try adding a strip or three of electrical tape to the rear of the mechbox to try to force it forward in the direction of the hopup.




Lights out

[GI Joe]

Good idea Lights.  I think it is something picky like that, or perhaps how the nozzle aligns with the bucking.  The original nozzle had no o-rings and had a pretty flat tip, however the new one is tapered at the very end (like most nozzles I have seen).  The difference there might be what is causing it to leak unless I get it aligned just right.

[Priest]

im having a similar issue with an aug a3, the hop up works, but the range is like 50ft. and at mc3 the gun chronoed at around 240 fps. which the gun should be 425-470 due to the 650 6.03 TB in there.

[Northern Lights]

Priest bring your AUG to the game and I will show you how to fix that. It is common with AUG's but is also easy to check for and fix.



Lights out