From the posts I've seen I get the impression it is a stripped M113 with a gun?

Guntruck-----What is it? Well, it is a very generic term that I believe originated during the vietnam war (Guntruck correct me here if I am wrong). The term "guntruck" was applied to US wheeled vehicles that were modified to carry extra weapons for convoy escort duty or troop support. Additional armament ranged anywhere from single or multiple M-60 or M2 machine guns to .30 cal gatlin guns or a WWII era quad M2 machine gun mount.

There were M113's that mounted a M-60 machine gun or gatlin gun(or other weapons) on each side to compliment the weapon on the commanders cupola but these were commonly referred to as "ACAV" or Armored Cavalry Assault Vehicles".

Vehicles typically used ranged from the US M151 series jeeps to 2 1/2 ton and 5 ton trucks. APC's weren't typically used for convoy escort due to their limited top speed and slow acceleration. There were cases of M113 hulls being mounted in the bed of 5 ton trucks though.

I could go on but feel other board members will have additional information to add. I hope this helps though.

During US Army deployment to Haiti in the mid-1980's, the 10th Mountain Division returned to the "hardened" truck concept and armored up a M923 5-ton cargo truck in the same fashion as the early Vietnam-era trucks. (Hint Hint for you guys itching to do something with that Italeri model kit - photo on cover of Museum Ordnance Magazine) Sharing the same lineage in concept as the Vietnam trucks, this qualifies it too as part of the "Gun Truck" line.

Gunnie

Charles,
No luck. The 5-ton was armored on the Cab and Bed with plate steel. .