So my friends stock MP5 spring shoots around 360 FPS which is too high for our local indoor area(320 FPS), so we went a picked up a "Power Mega hand made spring" aka PDI 120%. The guy said "it'll shot around 300 FPS". But yesterday at an indoor game, he tested out the FPS and it shoots around 330 which is still too high...
Could someone tell me did the dealer wrong about PDI 120%?
Or is my friends' MP5 went crazy?
I need to change my spring for my M4, but now that I see the issue, I'm not sure if I should just change it and test it or just return for a lower FPS spring.