Nozzle & Hop up not aligning properly - causing slight air leak

[perky416]

Hi guys,

I have a Umarex G36C, all of a sudden over the space of 2 or 3 days at airsoft the FPS dropped from 300 and finally settled at around 280, indicating I had an air leak somewhere.

I looking to see if anybody can assist me in solving this very annoying problem. The story so far...

I tried everything I could to fix, new piston, piston head, nozzle, bucking, dental floss on bucking, hop up, swapped the prommy barrel with the original, nothing fixed it.

After throwing the 300fps spring away (i forget what it was, perhaps a guarder sp90) I fitted a prommy ms100 which is firing at anywhere between 300 and 320 fps.

After a lot of faffing around I think I have found the problem, the nozzle and the hop up are not aligning correctly.

I originally inserted a piece of cardboard between the receiver and the thing that holds the barrel in the receiver (as per the attached pic, please ignore the clear plastic im still experimenting) to raise the hop up slightly and hey presto it was shooting at a nice 330 - 336 fps. I even removed the cardboard and refitted it again to make sure it wasn't a fluke...it was still shooting at 330 - 336 fps.

1.jpg

However the next day when I stripped it and tried to come up with something more permanent the fps wont go above 320fps no matter what thickness cardboard I fit.

And now we come to the present...with no cardboard fitted, when I put a slight bit of upward pressure on the hop up with a screwdriver (please see the other attached pic) it shoots at anywhere from 227 fps to 336 fps.

2.jpg

Has anybody had this problem before or does anybody know of a good way to align the nozzle and hop up?
Regards
Lee