That's a rifle length gas system.
Midlength with a 16" barrel gives you the correct distance from the sight base to the flash hider for bayonets.

My question is why would anyone bother putting a carbine or mid length gas system on a 16" barreled rifle that has a rifle length handguard and front sight/dummy gas block (other than to save a few $$ on production)
They probable started out using the carbine system ,like back before anyone even thought about a mid-length system.
Yeah,you need so much barrel in front of the gas block for the action to work,don't think you could do that with a rifle length system.
Anybody know if this is plausible?




























