Rucksack M1952 type 1
FSN : 8465-261-6931
Thanks to : Dgah 78
M1952 backpack with metal frame. it is OD green as opposed to the kaki colored WWII Mountain packs. It was commonly used by SF troops and LRRPs due to its large carrying capacity. All the leather straps are very pliable. It has the weapons strap.
Photo Credit : Here
This was the pack used early in the Vietnam war and was favored by Special Forces and even Airborne troops as it was bigger and handier to use than the issue M1945 2 pack system as used by the Army then. This looks similar to the WW2 Mountain pack as it was copied from that design but the color is Green instead of the Khaki shade OD of WW2.