WE KAC PDW really low fps/range

[THE FNG]

Hi all,

Having issues with a KAC open bolt PDW.

Bought 2nd hand, apparently has an NPAS installed.

The issue is very low fps at around 45-90 and a range of about 10 -15 feet if I'm lucky.

The gun cycles well and it does't actually sound too sluggish or slow. I am ordering an NPAS key as it didn't come with one, so I don't know if the setting is way below where it should be. Should this not be the issue, does anyone have any way for me to troubleshoot the issue? The hop is currently set all the way off and there are no blockages to the barrel.

Thanks in advance!

 

[sjhirst]

Hi,

Could well be the npas is set way too low!

There's a video here: https://www.youtube.com/watch?v=tzQIlF8VMHs

Skip to 11  minutes in to see the npas setting, as I can't remember off hand but i think it might be set too far out.

 

[THE FNG]

Hi,

Could well be the npas is set way too low!

There's a video here: https://www.youtube.com/watch?v=tzQIlF8VMHs

Skip to 11  minutes in to see the npas setting, as I can't remember off hand but i think it might be set too far out.

Got the naps key and did some adjustments, now hitting well over 300 fps!

Have accountered another issue though now; 1st round flies out at 300 plus fps, 2nd round gets stuck somewhere and slides out of the end of the barrel when the gun is pointed downwards. Gun also sounds really slow and sluggish, any ideas?

 

[Wo1f]

Could be the B.B. being pushed past the hop rubber if the chamber is empty. If one rolls out of th barrel but it shoots another B.B. when fired, it could be bolt bounce double feeding a B.B. 

 

[THE FNG]

Could be the B.B. being pushed past the hop rubber if the chamber is empty. If one rolls out of th barrel but it shoots another B.B. when fired, it could be bolt bounce double feeding a B.B. 

The first round of the mag fires with no issue, then any rounds after get stuck/dribble out of the barrel. 

 

[Wo1f]

The first round will come out normally because you manually cycle first to load a BB.  There’s usually less force doing that than when the gun cycles 

is your hop up fully on or off? I’m 

 

[THE FNG]

The first round will come out normally because you manually cycle first to load a BB.  There’s usually less force doing that than when the gun cycles 

is your hop up fully on or off? I’m 

Hop is fully off, have double checked the barrel and it's clear.

 

[Wo1f]

Try to turn the hop on 3/4 to see if there’s then enough resistance there to hold the bb.

 

[THE FNG]

Try to turn the hop on 3/4 to see if there’s then enough resistance there to hold the bb.

I think your advice has done it. GOT a consistent 340 fps reading now!!! Can't thank you all enough!

Only problem now is that it is struggling a bit when firing rounds in quick succession; can fire 6 or 7 shots then it gets sluggish and eventually vents all the gas through the barrel

 

[Wo1f]

I think your advice has done it. GOT a consistent 340 fps reading now!!! Can't thank you all enough!

Only problem now is that it is struggling a bit when firing rounds in quick succession; can fire 6 or 7 shots then it gets sluggish and eventually vents all the gas through the barrel

No worries. What gas do you use?

 

[THE FNG]

Primarily nuprol/WE green 2.0, but have been testing on with a can of player choice stuff which was on offer at firesupport I believe. 

 

[Wo1f]

Primarily nuprol/WE green 2.0, but have been testing on with a can of player choice stuff which was on offer at firesupport I believe. 

that aeg ultrair stuff? white and goldish coloured tin? if so, throw it in the bin lol. none of my GBBR's like that stuff. nuprol 2.0 is okay but id run propane personally. whats the range like? is it overhopping at all?

 

[THE FNG]

that aeg ultrair stuff? white and goldish coloured tin? if so, throw it in the bin lol. none of my GBBR's like that stuff. nuprol 2.0 is okay but id run propane personally. whats the range like? is it overhopping at all?

Yes that's the one!! Yea it's pants, only bought it cuz it was cheap. 

I've not had chance to test the range properly yet but I'm more than happy with the fps output.