Inconsistency problems WE M4 gbb

[pinksoda]

Ok, I know that gbbrs are relatively inconsistent but to difference of maybe 10-15fps. But my WE M4 shoots more than unusually inconsistent fps.

My chrony would read 333, 250, 302, 289, etc. Really inconsistent.

I have compared the stock bcg to the ratech bcg with the aluminum nozzle. I also tried using the aluminum nozzle with the stock bolt carrier. I would still get the same results.

What could be causing this?

[Drake]

I've found NPAS helps consistency (dial down the FPS if needed); ambient temperature will affect this. A heavier recoil buffer seems to help sometimes (keeps the valve open longer).

Also make sure your piston head is well lubed (I use 30wt silicone oil)

I use a stock bolt carrier, I don't know about the RATech bc group.

[pinksoda]

i used the AI grande oil for the o ring. Current setup is stock bolt carrier with aluminum nozzle. set it to the 300's but shoot from 250 to a little over 300. Very inaccurate over 30 feet. Will map gas help with my testing? Will it minimize cold pressure issues?

[Kos-Mos]

My friend has the same issue with the RATech aluminum nozzle/NPAS.

And reading online a bit, you are not the only one.

I would go with the steel bolt carrier and plastic nozzle, with NPAS.
You need a fuse part. A nozzle is cheap and easy to replace. Hop-up chamber, not so much.

My friend did go back to plastic nozzles and all is good now.

[Drake]

Originally Posted by pinksoda

i used the AI grande oil for the o ring. Current setup is stock bolt carrier with aluminum nozzle. set it to the 300's but shoot from 250 to a little over 300. Very inaccurate over 30 feet. Will map gas help with my testing? Will it minimize cold pressure issues?

250-300 is pretty low: did you lower a lot with NPAS or is it because it's really cold? (not sure where you're shooting, indoor/outdoor)

If its a cold temp issue than yeah MAPP/Pro should help.

[Kos-Mos]

Originally Posted by pinksoda

i used the AI grande oil for the o ring. Current setup is stock bolt carrier with aluminum nozzle. set it to the 300's but shoot from 250 to a little over 300. Very inaccurate over 30 feet. Will map gas help with my testing? Will it minimize cold pressure issues?

Made me think about it.

My friend goes through 1-2 o-rings every game. The steel bolt carrier has to be filed rounded so it stops cutting the o-ring.

The aluminum nozzle is aggravating the issue, as it's hard and has sharp edges. Might be good to file these too (minimal radius, just to blunt it).

[Thenooblord]

most cases with poor performance and wild FPS fluctuations on my WE rifles its the hopup not retaining the BBs, so the BB rolls a bit past the hopup before the gun is fired, so its got no pressure behind it and no hop so itll lost lots of fps and wing off randomly out of hte barrel, which is what it sounds like you said it does, try turning up the hopup, or using a different hopup rubber
easieast way to test for this is load up the gun, and shoot it downwards (into a pillow or something on the floor) and wait 5-10 seconds between shots and see if BBs occasionally roll out the barrel onto the floor

[pinksoda]

Originally Posted by Kos-Mos

My friend has the same issue with the RATech aluminum nozzle/NPAS.

And reading online a bit, you are not the only one.

I would go with the steel bolt carrier and plastic nozzle, with NPAS.
You need a fuse part. A nozzle is cheap and easy to replace. Hop-up chamber, not so much.

My friend did go back to plastic nozzles and all is good now.

Steel bolt and plastic nozzle seemed to work. But had to change the valve spring to a stiffer spring. It currently shoots 344-376 but most shots are around 355-366 with propane btw. This time I will check the hop up.

Although, it seems that the fps have regulated. The flight path of the bbs is still inconsistent. Out of 5 shots 1-2 shots would go downwards with in 10-20ft.