[Solved] Severe compression issue.

[Boyso]

Well, I've been trying everything, and I'm having a real hard time figuring this issue.

Basicly, with a Modify S110 spring, I'm getting 150 fps (With my Xcortech 3200).

I tested the compression parts of the gearbox, and I'm getting perfect airseal (ARS Mask kit 2G cyl. head, Modify nozzle, Modify piston head & piston, Modify Cylinder, stock JG tappet plate). I sanded the front of my tappet plate a bit also.

Now, my hop up is a Madbull ultimate with a Madbull bucking, and a Madbull tighbore. I added a layer of teflon tape on the outside of the hopup where the Cclip is, just to make sure.

So I do believe the leak is within the Nozzle -> Hopup, as there is a bit of friction between the hopup and the upper receiver. I file down the "wings" on the side of the hopup, but it doesn't seem to help much. The hopup seems to touch the gearbox.

I've heard the bucking was crap, but could it be the only reason for such a low FPS? I was getting 315 fps with my S90 spring before, and the new spring is much stiffer, so I doubt it could be the spring being a lemon.

Thanks for watching.

[Thenooblord]

I had a madbull ultimate hopup in one of my old ARs that got shit airseal, next owner put a prometheus in it and it worked perfectly, so that may be your problem right there

[Crunchmeister]

For testing purposes you could always install a regular hopup and see if that changes things. Then you can confirm where the problem lies.

And that new Madbull hopup seems to get some really mixed reviews.

[Boyso]

I know, but it was a one time mod to the plastic receiver to install a metal hopup, I can't put back the original hopup :P

Guess I'll look for a friend with a metal hopup to loan then :P

[Thenooblord]

I use a G&P in mine, its not an AR, its an MP44, but it takes M4 internals, anyways, It shoots 308+/-3 or so FPS with .25s, so id say its a good bet, BUT you need to shim the adjustment wheels cause mine were so loose you could literally blow on it to adjust the hopup

[Boyso]

Yeah but the thing I don'.t get is why I had no problems before. I'll try swapping buckings, and reinstalling the hopup, maybe there's something there.

[Thenooblord]

well hwat was changed between "then" and "now"

[Boyso]

Spring. S90 to S110

315 fps to 150ish

But like I said, I move around the hopup and as there is some friction with the upper receiver, I may have replaced it wrong :P

[Thenooblord]

changed nothing other than the spring?
and didnt lose the spring that goes in front of the hopup to push it back to the mechbox right?

[Boyso]

Yep, only the spring was changed. The spring on the hopup is still there.

I'll grab my trusty dremel and make more room :P

[Thenooblord]

change back to the 90 and check again just to eliminate the spring, it seems unlikely but the portion of wire for the spring could have been incorrectly treated and not have the correct tension or w/e, I'm no metallurgist

[Kid]

Did you change the nozzle? Not all V2 guns use the same nozzle length. Could you have put in a nozzle that is too short?

I received a gun once that had a severe air seal issue and it only shot ~20 feet. I changed the nozzle to a longer one and it shot just fine.

You would not be the first one in this thread to make this mistake...

[Thenooblord]

I still blame that on incorrect packaging, cause I ordered an AK nozzle

[Boyso]

Ah. HA!

Found the culprit.

Let's just say I won't buy anything from ARS ever again, I believe.

I'll snap a pic in a second.

EDIT : Here it is :

[Thenooblord]

oh no tahts fine, just duct tape it back on and its good to go!