low Compression?

[netruamas]

Ive got a M16 with a 495mm 6.03 barrel a m115 spring and a chrome cylinder w/ no port. It also has a high toque motor and I'm using a 10.8v NIMH battery. despite this it is shooting around 300fps, so it must be a compression issue right? What could I do to remedy this? Also Im looking for an fps around 390-420

[Jester316]

Check all your seals...

Barrel to hop up
Hop up to gearbox
Cylinder head to cylinder
Piston head to piston

Put your finger over your barrel as you fire. Can you keep air in the barrel by doing this, or does it leak out other places.

[netruamas]

Good ideas all around, I found that my piston head was the issue in the cylinder so I am replacing that. However there is a seal issue with my hop-up, not as bad as the piston head, but still an issue. What can I do to fix the hop up seal?

[Jester316]

Wrap a couple wraps of teflon tape round the hop up bucking where it meets the barrel to seal it off.

[Alien_Hunter]

Wrap a couple wraps of teflon tape round the hop up bucking where it meets the barrel to seal it off.

Are any FPS lost between the nozzle and hop chamber? This is something I've wanted to know.

[Gilligan]

http://www.youtube.com/watch?v=QInMxQPKyb8
This is a good way to ensure good seal between bucking and barrel.

To test the seal from nozzle to chamber, you could place a tiny piece of tissue paper in the mag well over the feed tube and cycle the gun a few times.

[Black Fox]

AH

Don't know if you solved your problem or not but go here.
http://airsoftpacific.com/viewtopic.php?f=13&t=30907