.50 CALIBER HEADSTAMPS
Manufacturing Marks of WWII

© Jerry Penry

The Browning M2 machine gun was the most widely used weapon on the American bomber and fighter planes of WWII. Due to the high demand of ammunition for this gun, many companies began producing the .50 caliber round to keep the supply available.



BROWNING M2 MACHINE GUN



Approximate Actual Size.

The .50 caliber round is 5.5" (140mm) long with seated bullet. The casing alone is just under 4" (100mm) long. The primer end of the casing where the headstamp is located is 0.75" (19mm) diameter. The bullet is typically 2.25" (55mm) long with 0.75" (19mm) seated into the casing. The bullet diameter is 0.50".



Remington Arms 1942 headstamps.


Known manufacturers and headstamp codes of companies producing .50 caliber ammunition during WWII.

DI = Defence Industries Limited - Ajax, Ontario, Canada.
DM = Des Moines Ordnance Plant - Ankeny, Iowa.
FA = Frankford Arsenal - Philadelphia, Pennsylvania.
KS = Kelly Springfield, Allegany Ordnance Plant - Cumberland, Maryland.
LC = Lake City Army Ammunition Plant - Independence, Missouri.
LM = Lowell Ordnance Plant - Lowell, Massachusetts.
M = Milwaukee Ordnance Plant - Milwaukee, Wisconsin.
RA = Remington Arms - Bridgeport, Connecticut.
SL = St. Louis Ordnance Plant - St. Louis, Missouri.
SR = Royal Ordnance Factory - Spennymoor, United Kingdom.
T = Tikkakoski Arsenal - Finland.
TW = Twin Cities Ordnance Plant - Minneapolis, Minnesota.
U = Utah Ordnance Plant - Salt Lake City, Utah.
UT = Utah Ordnance Plant - Salt Lake City, Utah.
WRA = Winchester Repeating Arms - New Haven, Connecticut.


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Headstamp Images Only
(No Text)
HERE

The headstamps shown below do not reflect all of the .50 caliber casings that were made during WWII.
If you have additional information or would like to contribute an additional or better photo of a headstamp,
please contact me. Headstamp images are approximately 2.3x actual size.

Refresh your screen if one or more of the images below do not appear.


Defence Industries Limited
The town of Ajax, in Ontario, Canada, was founded in 1941.
It was the largest defence industry in North America for the Allies.


1942


Des Moines Ordnance Plant
Operated by the U. S. Rubber Company from 1941-45.


1942


1943               1943               1943


1944             1944               1944

 
1945               1945


Frankford Arsenal
Operated as a major ammunition manufacturing plant from 1816 - 1977.


1939


1940               1940

 
1941               1941

 
1942               1942

 
1943               1943

 
1944               1944



Kelly Springfield, Allegany Ordnance Plant
Operated by the Kelly Springfield Tire Company in 1943-44.


1942


1943


Lake City Army Ammunition Plant
Established by Remington Arms in 1941 to manufacture and test small caliber ammunition for the U.S. Army.


1941


1942

  
1943                 1943                1943

     
1944                 1944                 1944                1944


1945

Note: The second 43 is the result of a broken headstamp die for the "L".



Lowell Ordnance Plant
A small arms plant that operated under contract from the
Remington Arms Company between 1942 and 1943.

 
1942               1943



Milwaukee Ordnance Plant
Operated by the U. S. Rubber Company from 1942-43.


1942

 
1943               1943               1943


Remington Arms
Founded in 1816, this company is the oldest in the United States which still makes its
original product, and is the oldest continuously operating manufacturer in North America. The RA 41 .50 CAL Z shown below was produced during a British RAF contract to supply ammunition for the American made B-17 bombers used by the RAF.


RA?
(The above was found among many RA 41 casings, so believed to be Remington Arms).


1941               1941


1942


1943


1944


St. Louis Ordnance Plant
This plant was operated as the United States Cartridge Company as a division of Western Cartridge Company. They were only a few miles east of the East Alton plant operated by Western.
This plant manufactured 6.7 billion .30 and .50 cartridges for the War.


1942               1942


1942 Overstrikes

 
1943             1943


1944


1945


S424


Spennymoor
Royal Ordnance Factory. Spennymoor, United Kingdom (1913-1945).

 
1942             1942


1943


1944


Tikkakoski Arsenal - Finland

Tikkakoski was the first private arms manufacturer in Finland. The arms factory was closed in 1987. Beretta Group owns now the Tikka arms brand. The United States supplied Brewster Buffalo fighters to Finland who was at war with Russia from 1941-1945. The symbol is a circle with crossed arrows. The 12.7 is the equivalent size of the .50 caliber in millimeters.


1942


Twin Cities Ordnance Plant
Operated by the Federal Cartridge Company from 1941-45.
This company produced .30, .45, and .50 caliber ammunition.


1942             1942             1942

 
1943             1943             1943


1944             1945


1942
(Broken Die)


Utah Ordnance Plant
Operated by the Remington Arms Company.


1942               1942


1943               1943


1944?


Winchester Repeating Arms


1942                  1943



Russian
This headstamp is of an unknown Russian manufacturer. The casing is a 12.7mm, the equivalent to the .50 caliber.


1944

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Pre-WWII Headstamps

 

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Regular M2 casing (top) shown with a short casing.
The short casing is from a .50 cal spotter rifle attached the 106mm recoiless anti-tank weapon. Its use was to simulate the exact trajectory of the main gun so to minimize misses.



Steel links connect the casings together.
Links also have manufacturing marks.
Click the link below to enter the "LINKS" website.

LINK MANUFACTURERS

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Wikipedia Website           Wikipedia Website
(.50 Caliber Shell)            (.50 Caliber Gun)


CONTRIBUTORS
Thanks to the following contributors who have supplied information or images for this website:
Danny Benger, Andrew Brock, William Browne, Fred Butt, Chuck Clark, Dave Clarke, Chris Collins, Mike DeFazio, Alicia Garrett
Jay Holton, Koen Jansen, Kori McCaskill, Gary Muckel, Joe Pilbeam, Gerald Stutts, Gene Thomsen, Ian Wood.



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