Is it reasonable to make a 14.5" middy, or would that move the muzzle too close to the gas port to function reliably? Does anybody make such a critter?

yes, been around for a few years now....

The Noveske Aghan barrel is a 14.5 midlength.

The Noveske build I'm putting together centers around the 14.5'' Midlength "Afgan"

Our midlength 14.5" concept was proposed about four years ago, the original proof on concept rifle was the Aardvark, this was the design that saw testing. This is a picture of what I believe was the 3rd or 4th incarnation of the Aardvark (the original is way too ugly to show on here!).




Shortly after this, the M4Ward was started, I can not show you a picture of it, but line art is okay... The M4Ward has a gas port located sort of at the midlength position, but some adjustments were made.



the Enhanced Battle Receiver (EBR) came out of all of the above and features the midlength system with a 15.5" barrel, a very nice system.

The Afghan barrel mentioned is probably very close in design to a mission specific design that was done up a few years ago, this drawing should give you a good idea of the size... it is beefey! Note the cut for the can, it is intended to use one.



If you want a good barrel, to your specs, hit up Randall there... he can not only guide you in the right direction, but he can make it happen.

eta: just to make some people happy... the Aardvark, M4Ward and Enhanced Battel Receiver are the design and property of Guerrilla Small Arms Research, all other designs are owned as indicated and posted with the respective owner's permition.