Fn2000 I got in a trade. Was told it had gearbox hopup spacing issues. Replaces hopup and installed a madbull TBB 6.03 with ML bucking. Has normal semi auto firing issues. Needs new trigger unit. Also still has spacing issues for gearbox and hopup. I’m not to techy so im at a loss for what to do. Looking to hand off to someone else who knows better. Comes with one mag and the flashhider