Whats the barrel length on a mid length upper?

[ghostman1960]

16, 18, or 20 inches? Thanks.

[MattS67]

16". Carbine length, different gas system.

[furioso2112]

There are also 18" (or will be soon, from BCM).

[WellArmedSheep]

Mid-length refers to the gas system length, not the barrel length.

The carbine-length gas tube is about 7.5 inches, the mid-length gas tube is about 9.5 inches long, and the rifle length gas tube is about 11.5-12 inches long.

[RMTactical]

Barrel length can differ.

[NeverMore1701]

There is supposedly a 14.5" midlength in the works from BCM. Couple that with a lightweight barrel, and it just might be something I'll have to add to the list.