G & P M4A1 (gp281c)

[dodgetheram]

how do i go about finding out what kind of spring my gun has?

[ShelledPants]

Use a chrony for exact FPS measurement.

An example of a chrony: http://www.airsoftparts.ca/store2/in...oducts_id=1181

[ArcticFox1984]

Or this if you don't wanna spend more then $1.00

http://redwolfairsoft.com/redwolf/ai...il?bulletID=34

[ShelledPants]

Originally Posted by ArcticFox1984

Or this if you don't wanna spend more then $1.00

http://redwolfairsoft.com/redwolf/ai...il?bulletID=34

This method is ridiculously inaccurate as aluminium can manufacturing varies broadly from country to country / province to province. At sub 350 FPS this method works to some extent, but after 400 you start seeing all sorts of bizarre results.

[dodgetheram]

I get 360 to 375 out of it...