M4/M15 issues, gun fires full auto in semi auto
 

What normally causes an M4/M15 style AEG with a v2 gear box to fire full auto in semi auto mode? I'm almost embarrassed to ask but I've checked the selector, the switch, the spring, and this guns being temperamental as hell.

What brand is it?

My recently upgraded TM MP5 RAS was having the same trouble, it would fire in full auto in semi mode. But it eventually worked itselft out of it after I'd switched to full auto and fired a clip or too in that mode. Sry, but i cant say what caused this or how it was fixed.

tappet plate is too weak, get the systema spring set for 8 bux throught group order

I'm a Systema dealer, don't need a group buy :)

I finally tracked down the problem in this gun. The selector plate was warped. I hadn't taken it off the mech box so I hadn't noticed.

Due to the warped shape, it wasn't engaging the semi auto lock