Developed as part of the experimental Marine Corps XM1964 load carrying equipment, the M14-H pouch was designed to carry two M14 magazines, horizontally one behind the other. It featured a Velcro fastener, two belt slide keepers, and was produced in both cotton duck and nylon by the Marine Corps Landing Force Development Center.
The XM1964 gear was tested by the 1st Battalion, 6th Marines at Camp Lejeune (North Carolina) and at Camp Garcia (Puerto Rico) between February and June 1966. However, extensive crawling by the wearer and exposure to mud caused the Velcro fastener on the horizontal pouch to fail. In addition, Marines reported that the horizontal divider made loading the pouch difficult. Consequently, though the vertical M-14V pouch was approved for further devlopment, the M-14H pouch was rejected.1
1. Marine Corps Pack XM1964, Army Field Pack, Combat M1961(Modified) Feasibility Study. (Marine Corps Land Force Development Center 1966)