i think i screwed up my gun...
installed:
pdi190 spring (brand new, japan made, packed in plastic box)
CA 7mm metal bushings
systema shims
edgi 6.03mm ID tightbore barrel 510mm length heheheh
systema hop rubber (the stock hop up sucks after consuming half a bag of BB)
the resulting fps? ngak! only 440 fps!!!!!

i reached 440fps using the same upgrade but with sp120 spring on a AUG..
then, what i did:
sealed the cylinder head with teflon tape
changed the piston head O-ring with a thicker one
slightly increased the porting hole
di pa nachrochrono

sana tumaas fps ko huhuhuhuuhuhuhuhuh....
ano pa gagawin ko para mawala leaks? duda ko kasi massive air leak to eh