Originally Posted by Cobalt Caliber
And G&G piston heads probably have horrible piston compression
Because of this everything you've said should be considered irrelevant because you don't actually know how the gun, or brand for that matter, operates and this comment in itself is hypocritically "childish".
I've owned a G&G PM4 Light for almost 2 years and it hasn't had a problem yet. The only things I changed were putting high speed gears by Element and a Madbull tightbore inner barrel. Everything else internally is stock and it shoots a consistent 375-380fps.
There are better guns and perhaps some retailers price things higher or lower than others but welcome to the current Canadian airsoft market.