KSC Glock 19 has no blowback

[Ghillie973]

I've read through some of the previous post regarding blowback problems but I'm not sure what the solution might be.

When I fire my glock it acts as if it's a NBB. I mean there is little to no movement of the slide. Now would this be caused by the rocket valve or the piston head? When I took it apart I noticed the rocket valve can move around inside the nozzel. Is this normal or is the valve worn out?

Any help would be great, thanks guys.

[ILLusion]

sounds like your rocket valve may be broken. Check to make sure the stem is still attached to the cap.

[ILL9MIL]

Had you recently taken out the loading nozzle from the blowback chamber? If so perhaps the two blowback chamber springs were put back in improperly. They go in after you put the loading nozzle into the blowback chamber, they should be fullly uncompressed when you put the chamber back in the slide.

The floating valve sits on a spring and can move around slightly back and forth, it shouldnt be loose shaking around inside tho.l

[Ghillie973]

Just the man I was looking for...

I took it out last night and it still has the stem and the fins. When I say it moves around, I mean it doesn't sit straight inline with the nozzel. I can tilt to any side. Is there a chance the fins could be worn down and make the valve not work properly?

I think I will buy the Firefly Valve just to make sure. If it doesn't fix it atlease I know that's not the problem.


EDIT for ILL9MIL:
I was told those springs don't affect the blowback, they just keep the nozzel back. Either way, one was bent a while ago and I cut off the bent section and streched the spring to the proper length.

Like I said, the rocket (floating) valve isn't shaking around. It's still attached to the nozzel spring but it sits canted to the side.

The blowback works fine when I fire it without any BBs. When I load up the mag with BBs there is no blowback.

[ILLusion]

It sounds like some kind of issue with the rocket valve.

The way a GBB works is that the rocket valve remains opened as long as the BB is in the barrel. It provides enough backpressure to keep the valve open. Once the projectile leaves the barrel, a negative backpressure is created in the barrel and the higher pressure gas from the magazine pushes the valve shut, and thus, redirecting air into the blowback chamber.

If the valve is damaged in some way in that it can not be directed to close the nozzle, then the blowback cycle will not occur.

Since your gun seems to blow back with no ammunition, further investigation of the unit and parts are required.

[Ghillie973]

Awesome, thanks Illusion.

EDIT: Problem fixed. Installed an new Firefly Rocket Valve and now it works perfect. Thanks for all your help guys.