[Deaf_shooter]

My brother open up gearbox and replace one stuff(I haven't ask what is name of thing he replace. It look like tube that attach to one end of spring) then put all together under direction of youtube (not whole, just 2 gear left that has do with semi and auto selector). when he test it, he manage to get one shot before it jam. Motor still run but gear won't move, my brother and I try to move but it is stuck.