Help - Have I broken our HP PPSH's?

Just sounds like an airseal problem. If you havent opened the gearbox. Where the hop, barrel and gearbox all join up just needs to be rechecked. Its probably not alligned correctly.

definatly an air seal fault ,sometimes the nozzle on the front of the gearbox is made a slightly different length ,this results in either no feed if the nozzle is too long or loss of power if its too short,the latter is probably what you have.if you'r in a hurry you'r gunna have to re fit the old hop's ,then order a pair of g36 nozzles to fit at a later date ,that will solve the problem .i swapped gearboxes between my thompson and p90 once ,both marui originals ,both v6 gearboxes ,one wouldent feed the other was down on power,i scratched my head for ages before noticeing about 0.75mm difference in nozzle length.doesent seem mutch but there's a supriseing level of prescision in hop chambers.

Thanks - that's what I suspected.

The trouble is, the way the PPSH breaks down with the hinged top bit, it seems completely random where the hop ends up when you fold the top cover back down. I guess I just need to keep opening and closing until it fits right but there must be a better way than that.

EDIT - reseated them and now both doing 280 ish so not too bad (we're used to being outgunned anyway).

EDIT 2 - Thanks Dadio - yes will try the nozzles at a later date that sounds like it could very well be it too. I'm reluctant to re-fit the old hops because they were so atrocious on Anne's one.

Thanks - that's what I suspected.

The trouble is, the way the PPSH breaks down with the hinged top bit, it seems completely random where the hop ends up when you fold the top cover back down. I guess I just need to keep opening and closing until it fits right but there must be a better way than that.

ive noticed this to mate, , what i do is this, when closeing the top down, hold the hop chamber from UNDERNEATH and push it forward, and try to close without trapping your fingers at the last minuite. its tricky but it can be done

I open up the bolt, stick my finger in there and push the hop unit forward when I close it up.

have you refitted the spring that slides over the barrel and sits behind the hop assembly ,if its there then the hop should sit tight against the gearbox as mine does when you close the reciever

I don't own one, so I can't say if it'd work, but what about fitting a magazine to hold the hop in place?

I don't own one, so I can't say if it'd work, but what about fitting a magazine to hold the hop in place?

with a magazine on the hop wont close down

Yes I did refit the spring and I thought that would pretty much guarantee a good seal (surely that's the point of it) but apparently not.

Opening the bolt cover as Yith suggests seems about the best way of getting it closed and in the right place.

280 - 300 fps with a decent hop should be way better than 330 without so I should just leave well alone now but because I refuse to admit my shortcomings I won't be able to resist further tinkering.

So I might try refitting one of the old hop outer units but just replace the rotating selector bit and the tiny bit that presses down on the hop bucking (they seem to be the worst parts of the stock hop). I think the problem with the ones that come with the gun is simply that the bit that presses down just isn't long enough to actually be pressed down enough by the rotating bit.

This might actually make sense to people who are familiar with the PPSH hop. I'll take some pictures if it works because it might be handy for other people doing the same thing.

yes that is the problem , i just glued a 1mm piece of plastic on the top of the adjuster and it worked fine.
the hop wheel was very loose on mine so i wrapped ptfe tape around the hop body as packing then refitted the wheel and it was alot better.

The spring should give the back pressure against the gearbox face. Looks like HP got it a bit wrong.

You can see how mine works in the one I made.

http://www.youtube.com/watch?v=0SKFLmDBsI8

Well this morning I switched them back to the stock Hop unit but with the replacement "twisty bit" and "tiny bit" and both are now back to 330-340 fps and now with working hops. Yay!

So it was definitely the airseal and Dadio was right; the G36 must be just a tiny bit smaller than the stock one, enough to make a massive difference anyway.

Thanks for everyone's help. I will post a separate thread with some pictures for future reference.

I replaced mine with a CA G36 hop chamber and it worked even better than the stock. So i guess it matters which brand you're using.

That's interesting.

Our ones are labelled "SHS" on the Airsoft World store here - http://www.airsoftworld.net/shs-g36-pps ... -unit.html

I also replaced my hop with a CA G36 one and put in a tightbore barrel. The result was a gun firing consistently over 360fps, so I replaced the spring and re shimmed the gearbox at the same time. The gun is definitely quieter now.