Airsoft Canada - View Single Post - Modify srock Systema cylinders (M90, M150, etc)

SBranson23 · October 18th, 2007, 00:09

Yup, as mcguyver said, an APS spring is the right diameter if you want to use a custom cut. I was working towards a 400fps or M120 spring so I started with the APS180. If you need 300 and don't really need the 320-330 or so of the M90 (mine shoots 328fps almost every time), I just suggest you cut the spring in your M90 down to an M80. Just cut a coil off, heat the end and bend it flat again and chrono it. Keep going until you get the FPS you want. It requires patience 'cause you don't wanna end up with an M75 if you don't have to. Very easy to do.

October 18th, 2007, 00:09	#14
SBranson23 Trader rating Join Date: Jun 2006 Location: Victoria,B.C.	Yup, as mcguyver said, an APS spring is the right diameter if you want to use a custom cut. I was working towards a 400fps or M120 spring so I started with the APS180. If you need 300 and don't really need the 320-330 or so of the M90 (mine shoots 328fps almost every time), I just suggest you cut the spring in your M90 down to an M80. Just cut a coil off, heat the end and bend it flat again and chrono it. Keep going until you get the FPS you want. It requires patience 'cause you don't wanna end up with an M75 if you don't have to. Very easy to do.