AUG shooting weak problem

[venture]

Finally, there is the most baffling case of all.

I got a CA AUG from a customer, he wanted to up the power as it was shooting very weak at 260fps. I put the strongest spring that the GB could turn and yet it still shoots about 260-280 with a 150% spring!!! Should be in the 400-430 range????

I checked airseal at the nozzle, piston head and hopup/nozzle interface. All are quite good. WHERE IS THE POWER GOING???

[Urrah!]

It is curse.




You must punish it by two minutes to midnight.

[Styrak]

Bad hopup rubber? Even if it doesn't look too bad, even slight wear at the nozzle end can greatly affect the airseal. I've seen it quite a few times.

[venture]

Originally Posted by Styrak

Bad hopup rubber? Even if it doesn't look too bad, even slight wear at the nozzle end can greatly affect the airseal. I've seen it quite a few times.

You know, it is the next logical thing to try. Thanks, Styrak.

I will update as things develop.

[Kos-Mos]

Does it still have the stock plastic hop-up chamber?
Most of the time, there will be a micro failure right in front of the barrel clip, and under pressure the crack opens and let the air out around the barrel.

Also try an other inner barrel and try without the outerbarrel extension (remove at the vertgrip). It can be bent just enough to put pressure on the inner and cause the BB to slow down near the end of the barrel.

[venture]

well, it was not the hopup ~ bucking or chamber.

thanks kos, that gives me a couple more things to try.

[Jimski]

also you can check if there is a leak between the hop unit and inner barrel...

[venture]

Well I put my Marui hopup with Madbull tb barrel into the thing and it still shoots weak.

I had thought the hopup/nozzle interface had tested well, but upon retesting the problem lies there. Airseal is terrible at the hopup/airseal nozzle. I replaced the nozzle and tried again. Exactly the same, massive air loss.

Any ideas how to fix this problem?

[Urrah!]

What is the barrel made of?

[venture]

The stock CA barrel is brass and the one from my TM is Madbull aluminum TB barrel.

[Urrah!]

Are the barrels clean? Was real gun oil used by accident on any of the parts? Is there maybe an FPS reduction piece in the nozzle?

[venture]

None of the above. It is a case of the nozzle not reaching into the hopup enough or something like that. the air is blowing down the feed tube into the magazine.

[Urrah!]

I'm sorry, but I cannot help you.

[Eien]

Is your nozzle on the cylinder head or on the tappet plate? Sometimes, I accidently put the nozzle in the cylinder head and not on the tappet plate.

[Reckless]

Ron.. this may sound stupid.. but make sure the gearbox is absolutely all the way forward... and the barrel assembly is all the way back and locking in without moving... and that the hop chamber is fitting right up/into the front of the gearbox.

Ive had 2 CA's across my bench ... one was horrid with fitment and matching CA/TM etc etc parts ... the other one one was magic the whole way.