WE HK416 Open Bolt issues - PLEASE HELP

[Kingpin665]

Alright, so I've installed an NPAS which went great and got the gun shooting in nicely under 400fps but couldn't get the hop up working right because it was defective. So I replaced it with (SEE LINK BELOW) and got the accuracy finally responding how an airsoft gun should, other than that the odd shot wouldn't shoot perfect like the last ten shots did but would drop out of the barrel and go maybe ten feet, and then the next ten would be great again. I had this happen over the course of about 16-20 30rd mags trying to break in the hop up.
Just curious if anyone might know why that's happening?

But outside that small issue my real problem is this, yesterday I went to a local paintball facility to use their chrony and get the FPS lowered enough to play at a CQB game capped at 360fps. After adjusting the NPAS I could get it shooting as low as 330-340 which is perfect... for the first shot, and then the fps would shoot way way up, always well over 400fps. It didn't matter how I extreme I adjusted it the gun was acting really strange.
When I originally installed and dialed in the NPAS with the old hopup installed it was shooting relatively consistently with maybe 10-15 fps drop/spike, which is fine. But now my gun is a paper weight since it's to hot to use at any game and it doesn't seem to matter what adjustment I make to the NPAS it ignores the tweak and goes back to shooting 420-440.
I REALLY don't understand how it can lower for a SINGLE shot but then fuck right off on me start shooting 60... 80...100fps faster for every shot after.



http://www.airsoftparts.ca/store2/in...oducts_id=2264

[Fox62]

Originally Posted by Kingpin665

Alright, so I've installed an NPAS which went great and got the gun shooting in nicely under 400fps but couldn't get the hop up working right because it was defective. So I replaced it with (SEE LINK BELOW) and got the accuracy finally responding how an airsoft gun should, other than that the odd shot wouldn't shoot perfect like the last ten shots did but would drop out of the barrel and go maybe ten feet, and then the next ten would be great again. I had this happen over the course of about 16-20 30rd mags trying to break in the hop up.
Just curious if anyone might know why that's happening?

But outside that small issue my real problem is this, yesterday I went to a local paintball facility to use their chrony and get the FPS lowered enough to play at a CQB game capped at 360fps. After adjusting the NPAS I could get it shooting as low as 330-340 which is perfect... for the first shot, and then the fps would shoot way way up, always well over 400fps. It didn't matter how I extreme I adjusted it the gun was acting really strange.
When I originally installed and dialed in the NPAS with the old hopup installed it was shooting relatively consistently with maybe 10-15 fps drop/spike, which is fine. But now my gun is a paper weight since it's to hot to use at any game and it doesn't seem to matter what adjustment I make to the NPAS it ignores the tweak and goes back to shooting 420-440.
I REALLY don't understand how it can lower for a SINGLE shot but then fuck right off on me start shooting 60... 80...100fps faster for every shot after.



http://www.airsoftparts.ca/store2/in...oducts_id=2264

Well, does the valve physically switch into a more closed position (higher FPS) after the first shot? Did you take it appart to check?


Fox.

[Fuzzy]

Add silicon oil to the nozzle oring. If the oring dries out, it will cause spitter shots and very inconsistent fps.

[Huron]

I have that bucking, and it doesn't grab BBs in a WE GBBR because the internal shape is different than a WE bucking. If you compare them, the WE is thicker all the way up to the hop up nub, whereas the Modify just has one ring inside it to form an airseal because it was designed with VSR-10 systems in mind. Try a stock WE rubber or one more similar to it and see if that helps, or find some way to make the Modify rubber tighter where the BB sits.

[Kingpin665]

Originally Posted by Fox62

Well, does the valve physically switch into a more closed position (higher FPS) after the first shot? Did you take it appart to check?


Fox.

On the fully closed position I didn't notice it opening up at all after I shot, with the nature of how the NPAS needs to be held in place so the adjustment tool doesn't just spin the entire piece rather than thread open/closed I wasn't worried about it but I will look again to be sure tonight.

I will also try adding some lube as was just also recommended by Fuzzy.

Originally Posted by GabeGuitarded

I have that bucking, and it doesn't grab BBs in a WE GBBR because the internal shape is different than a WE bucking. If you compare them, the WE is thicker all the way up to the hop up nub, whereas the Modify just has one ring inside it to form an airseal because it was designed with VSR-10 systems in mind. Try a stock WE rubber or one more similar to it and see if that helps, or find some way to make the Modify rubber tighter where the BB sits.

And lastly I bought that rubber through recommendation of the community and the retailer, I'm disappointed to find out it isn't quite compatable... but if the rubber were to loose as you say the Modify would be in relation to the stock WE wouldn't the fps be lower overall rather than spike as it is?

Thanks guys.

[Fox62]

Originally Posted by Kingpin665

And lastly I bought that rubber through recommendation of the community and the retailer, I'm disappointed to find out it isn't quite compatable... but if the rubber were to loose as you say the Modify would be in relation to the stock WE wouldn't the fps be lower overall rather than spike as it is?

Thanks guys.

That's the best bucking for OB WE guns. On some systems it may cause the BB falling out problem (has NEVER happened on my SCAR, even on the hop up at zero). It's 100% compatible, and about...500 times better than the stock bucking (in both seal, consistency and range). I run my SCAR on dry propane, so if you use Green Gas maybe the extra lube's allowing your BB's to roll forward, just leave your hop up slightly on and it should hold the BB's in place, adjust until they stop falling, and use that height as a base.


Fox.

[Kingpin665]

I use propane, I suppose I should have mentioned that earlier... and I do use a drop or two of silicone oil in the propane adapter because I was under the impression that it was best for the mags (no?). I also do have the hop up only sliiiiightly engaged right now for the accuracy I want and the BB won't fall out the end even if I turn the barrel down and shake the shit out of the rifle. I thought the new hopup rubber felt solid as a rock in comparison to the WE one I removed and was very impressed.

Also, I have re lubed both the O ring in the nozzle as well as the two inside the NPAS itself... but only the tiniest slightest amount. The nozzle O ring didn't show any signs of cracking or age (it is a brand new gun after all) but looked rather healthy.

[Huron]

If the BB isn't falling out of the barrel, then you don't have a problem with the bucking. Gotta be something else.

[pinksoda]

Where did you buy this gun? and does the box have a sticker of the canadian flag and says 400fps. They pretty much cut the nozzle to certain length that an NPAS fully closed would still wobble inside and give inconsistent fps. Bought the we scar with the same problem replace the nozzle with a new one problem solved.