Description
U.S. Browning .50 Caliber M2 / AN-M3 Barrel Extension Shank Lock Pin, P/N 5009268
Item Overview
This U.S. military barrel-extension shank lock pin is an original mechanical component for the Browning .50-caliber machine-gun family. Part number 5009268 secures the barrel-extension shank inside the barrel extension, helping the joined parts remain properly aligned during operation. This is not a firing pin, ammunition component, or complete firearm.
Identification and Features
The 1955 Army and Air Force parts manual lists one P/N 5009268 pin in the barrel-extension assembly used by the AN-M3 aircraft machine gun. The pin is made from steel and has a simple headless design for installation within the assembly.
- Official nomenclature: Pin, Straight, Headless
- Part number: 5009268
- Modern NSN: 5315-00-417-8254
- Material: Steel
- Diameter: Approximately 0.1255 inch
- Length: Approximately 1.50 inches
- Documented assembly: AN-M3 barrel-extension assembly, P/N 7312760
- Function: Retains the barrel-extension shank inside the barrel extension
- Item type: Internal mechanical gun component
Function in the Barrel Extension
The barrel extension was part of the Browning gun’s recoiling group. The shank projected from the rear of the extension and connected with the buffer mechanism. Pin 5009268 locked the shank into the barrel-extension body so the joined parts could move together during recoil and counter-recoil. It should not be confused with the larger breech-lock pin, which served a different purpose in the locking system.
Weapon Applications
Part number 5009268 is specifically documented in the AN-M3 aircraft machine gun’s barrel-extension assembly. The same basic shank-lock arrangement was used across the Browning .50-caliber M2 and M3 family. These recoil-operated, belt-fed guns served in aircraft, armored vehicles, ground mounts, naval installations, and defensive positions, although individual parts should always be matched by part number before being assigned to a specific model.
Historical Background
The Browning .50-caliber M2 family entered U.S. service during the early 1930s and became one of America’s most important heavy machine-gun designs. Air-cooled aircraft versions armed fighters, bombers, and gun turrets throughout World War II. The faster-firing AN-M3 was developed for postwar aircraft and served during the early Cold War and Korean War era. Small internal parts such as this lock pin helped keep the barrel-extension assembly secure under the repeated force of automatic fire.
Condition
This is a military-surplus steel component that may show storage preservative, finish wear, scratches, discoloration, oxidation, or other signs of age and handling. Markings and surface condition may vary. This listing includes only the barrel-extension shank lock pin or pins stated in the product options; the barrel extension, shank, firearm, ammunition, and other accessories are not included.
Ideal For
This small but correctly identified component is well suited for collections and exhibits covering Browning machine guns, American aircraft armament, and military small-arms development.
- Browning M2 and M3 parts collections
- AN-M3 aircraft-gun displays
- Military armament research
- World War II and Korean War exhibits
- Ordnance reference collections
- Museum and educational displays
Approx length 1.5", Approx width 0.1", Approx height 0.1", Approx weight 0.01lbs.
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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