Description
Browning M2 .50-Caliber Back-Plate Buffer Adjusting Screw, A152834 / P/N 5152834
Item Overview
This original back-plate buffer adjusting screw was made for the Browning Machine Gun, Cal. .50, M2, Watercooled, Fixed, Navy. The original Ordnance drawing and piece mark is A152834. The part was later identified as P/N 5152834.
The screw threads into the rear of the back-plate buffer tube. It retains and compresses the fiber buffer disks that absorb the bolt’s remaining energy at the end of recoil.
This component is part of the back-plate buffer assembly. It is not used to adjust the gun’s headspace or firing timing.
Identification and Features
- Official nomenclature: Screw, Adjusting
- Original drawing/piece mark: A152834
- Later part number: 5152834
- Application: Browning Machine Gun, Cal. .50, M2
- Configuration: Watercooled, Fixed, Navy
- Assembly location: Back-plate buffer tube
- Purpose: Retains and compresses the fiber buffer disks
- Manual reference: 1942 parts catalog, Plate 11
The screw has a large external slot for installation and adjustment. Its center opening accepts the spring-loaded adjusting-screw plunger. The plunger locks the screw in position and helps prevent it from turning during operation.
Function
During recoil, the M2’s bolt moves rearward and strikes the buffer plate. Fiber disks behind the plate compress and absorb the bolt’s remaining energy. This reduces damaging shock to the bolt, receiver, and back-plate assembly.
The adjusting screw closes the rear of the buffer tube and controls compression on the fiber disks. Correct compression keeps the disks firmly seated while allowing them to cushion the bolt.
This function is separate from headspace and timing. Headspace is adjusted at the barrel and barrel-extension connection, while timing controls when the firing mechanism releases. This screw adjusts only the back-plate buffer-disk assembly.
Condition
This is original military-surplus equipment identified by its military wrapper. Age-related storage wear, finish wear, discoloration, grease, surface oxidation, or damage to the wrapper may be present.
Markings, finish, and packaging condition may vary. Please review the product pictures for the represented condition.
This listing is for the adjusting screw shown in the product pictures. The back plate, buffer tube, fiber disks, buffer plate, locking plunger, spring, machine gun, and other components are not included unless pictured or specifically stated.
Historical Background
The Browning .50-caliber machine-gun family grew from a U.S. military requirement developed near the end of World War I. John Moses Browning enlarged his earlier machine-gun design to fire the powerful .50 BMG cartridge.
Water-cooled .50-caliber Brownings were used by the U.S. Army and Navy during the years before World War II. The water jacket surrounding the barrel allowed the gun to maintain fire longer without overheating. Navy versions were installed on ships and other fixed defensive positions, where their weight was less of a concern.
The M2 was built in several configurations, including water-cooled, heavy-barrel, aircraft, fixed, and flexible models. Many internal design features were shared across the family.
The 1942 M2 parts catalog illustrates A152834 in the back-plate assembly on Plate 11. A period Army technical manual also shows the adjusting screw installed behind the fiber buffer disks and identifies its plunger and locking spring.
The part remained part of the M2 design after World War II. The later military specification MIL-DTL-1298E lists 5152834 under the official name Screw, Adjusting, showing the continued use of the part number in the long-serving M2 weapon family.
Ideal For
- Browning M2 water-cooled restorations
- U.S. Navy fixed-gun displays
- M2 back-plate and buffer assemblies
- World War II machine-gun collections
- Historic armorer and spare-parts displays
- Military museums and educational exhibits
- Browning parts and drawing-number collections
Approx length 1", Approx width 1", Approx height 0.5", Approx weight 0.2lbs.
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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