Does anyone know the cheapest way to reduce the fps on a king arms m1a1 thompson down to under 350 fps
Replace the main gearbox spring, or take the existing one and cut it shorter (latter option is only as expensive as your cutter of choice).
Ok cheers mate
How short do you think i should cuf it to be lower than 350 fps?
Time consuming but cut one coil off at a time until you reach the desired fps.
Fitted the sten gun sight I designed on Shapeways. Pretty cool. 
- We don't stop playing because we grow old. We grow old because we stop playing -
- While growing old is mandatory, growing up is optional -
The way we do it to an air rifle is by heating the spring end up and gently pressing it till you get the length you desire.
This way saves cutting and finishing the spring.
Dip in water to cool spring end.
Cyma Thompson m1a1
AGM MP40
WE TT33 chrome
Well Webley .455 & loads of shotshells.
