Both ends on the YHM forearms are threaded. with the same thread.
Had someone take two of their carbine length custom tubes and screw them together to get a 14" tube.
Didn't look half bad.
Mag rounds down, pointing rearward. About 3" of mag stick up out of the holder.
Extended mag release that operates with the trigger finger.
Hit the release. Knock-it and rock-it with the new mag