Classic Army issue resolved... (hop-up to nozzle compression

[carlsbad0331]

Ok, I along with many Classic Army owners have issues with the mysterious loss of compression. I found what my issue was today and solved it and thought I would pass along my findings.
I gained an extra 35-40fps today, and Im pretty damn happy about it.
On the Classic Army outter barrel, there is a small hex head set screw that holds the barrel to the body. If this set screw is tightened too fasr it makes contact with the hop up and makes the hop up spring useless. This causes the hop to not fit properly against the nozzle.
I opened it up and found that the hop was tightened up against the body, and really not even able to move. I loosened the screw just enough to loosen the hop and put it back together.
Not only did the occasional double feed issue go away, I found about 40 more fps...

[Speedy]

Thanks for the useful tip
My fps didn't go up that much, but my distance nearly DOUBLED and i had no idea u could get this kind of distance with a CQB WOW. I can compete with snipers now.
Thanks again for the info

[pilz]

Thanks for the useful tip
My fps didn't go up that much, but my distance nearly DOUBLED and i had no idea u could get this kind of distance with a CQB WOW. I can compete with snipers now.
Thanks again for the info

Which screw is it? Also how do you get the top RIS unit off?

[carlsbad0331]

I dont know about taking the RIS off, my rifle began as a standard M15.
The hex head screw that I am referencing would be under your Barrel nut...
Today I opened it back up, threw a new SP140, Systema low resistance wiring set and a brand new piston. Chrono'd it and she is shooting between 525 and 535.

[pilz]

I dont know about taking the RIS off, my rifle began as a standard M15.
The hex head screw that I am referencing would be under your Barrel nut...
Today I opened it back up, threw a new SP140, Systema low resistance wiring set and a brand new piston. Chrono'd it and she is shooting between 525 and 535.

But i  can't take the barrel nut off with the RIS on. I took te top reciever off and i removed my barrel and looked in and i saw were the screw is. the screw is a few mm's in. So should i leave it because its not sticking out?

[Vince]

There's an allen screw at the head of the CA RIS, umm, loosen that and it loosens this little claw that grabs onto...something. After that, it should come off.

It's been a while since I did this, but, two percent rule...you can win if you try.

[carlsbad0331]

If your hop-up unit/ barrel moves in and out of the outter barrel freely, THEN THERE IS NO NEED TO CHANGE ANYTHING.
When I received mine back the last time it went into a shop, it came back so that you could not remove the hop-up/inner barrel from the upper receiver/outter barrel...