Postby KevOne » Sat Oct 03, 2009 3:52 pm
im looking to up the fps on my kwa m4 cqb. i purchased a systema m130 spring and when i installed it the gun would not fire. it seems that the spring is fully compressed before the piston is released. when i switched back to the factory spring i noticed the systema m130 was about a half an inch longer than the factory spring an M110. please let me know what i can do. should i not be using a systema spring? would a mad bull m130 fit