Description
Browning .50 Cal. Breech-Lock Pin Assembly, P/N 6008784
Item Overview
This original Browning .50-caliber breech-lock pin assembly is an internal component used in several military machine-gun installations. Part number 6008784 was documented for the AN-M3 aircraft gun, M2HB flexible gun, and M48 fixed or turret-type gun. This inert mechanical part is not ammunition and should not be confused with a firing pin.
Identification and Features
A 1955 Army and Air Force parts manual identifies this item as “PIN, breech lock, assy.” The complete assembly consists of breech-lock pin 5009274 and retaining spring 5009357. Its early Federal Stock Number was 1005-600-8784, while later records classified it as NSN 5315-00-600-8784.
- Official name: Pin, Breech Lock, Assembly
- Part or drawing number: 6008784
- Pin component: P/N 5009274
- Retaining spring: P/N 5009357
- Legacy FSN: 1005-600-8784
- NATO-style stock number: 1005-00-600-8784
- Later/current NSN: 5315-00-600-8784
- Weapon caliber: .50 caliber
- Documented applications: AN-M3, M2HB flexible, and M48 fixed/turret-type guns
- Approximate pin size: 2 inches long and 1/4 inch in diameter
- Status: Inert internal gun component
How the Breech-Lock Pin Worked
The pin retained the breech lock inside the barrel extension while allowing the lock to move up and down. During recoil, the ends of the pin contacted the breech-lock depressors. This movement forced the breech lock downward and released the bolt from the barrel extension so the gun could continue its operating cycle. The small retaining spring helped keep the pin properly installed.
Weapon Applications
Part number 6008784 was not limited to the M2HB. Military records also identify it with the high-rate AN-M3 aircraft gun and the M48 fixed or turret-type installation. These weapons shared the basic Browning short-recoil operating system, allowing important internal parts to serve across several configurations. The flexible M2HB was widely used on ground, naval, and vehicle mounts, while fixed and aircraft versions were built for specialized installations.
Historical Background
John Browning’s .50-caliber machine-gun design began near the end of World War I and developed into the M2 family during the years that followed. The M2 became one of the longest-serving American military weapons and saw wide use during World War II, the Korean War, the Vietnam War, and later conflicts. The AN-M3 was a faster-firing aircraft version developed near the end of World War II and used heavily during the early jet age. This shared breech-lock pin represents the durable internal design that helped the Browning system serve in aircraft, vehicles, ships, and ground positions.
Preservation-Pack Markings
Package markings help document this part’s supply history. “Qty. 6” means the package originally held six assemblies, while “Method IC” refers to waterproof-barrier preservation under MIL-P-116, with protective preservative applied when required. The “10/62” marking most likely records an October 1962 packing or preservation date and does not necessarily identify the manufacturing date. The meanings of the “WN” and “C1/AM” markings are unknown and may represent a warehouse, military activity, or inspector. The marked original quantity does not guarantee the number of parts currently included with this listing.
Condition
This is a military-surplus internal gun component that may show aged preservative, finish wear, scratches, discoloration, and corrosion from long-term storage. The damaged-looking area is consistent with deteriorated protective finish or preservative and surface corrosion. Package markings and the condition of individual pins may vary. Please check the pictures for the general condition of the item.
Ideal For
This breech-lock pin assembly is well suited for collections and exhibits covering historic Browning machine guns, military aircraft armament, and United States ordnance supply systems.
- Browning .50-caliber parts collections
- AN-M3 aircraft-gun displays
- M2HB historical exhibits
- M48 fixed and turret-type gun research
- Military armorer and ordnance displays
- Replacement-part identification studies
Approx length 2", Approx width .25", Approx height .25", Approx weight 0.1lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
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