Unknown .50 BMG Case


Can anyone ID this .50 BMG, 12.7x99, caliber cartridge case? Already checked with Bill W.

Seller couldn’t provide any info. Case is fired, further complicating ID.

It appears to have, originally, been a St Louis 1943 manufactured case, but has been modified as illustrated. It may have been some kind of blank in that it appears to have the case neck roll crimp similar to the M1 Red Topwad blank. It also has either been acid washed, copper plated, or painted with some sort of gold finish similar to those EOD blanks with the wire pig tail.

The original case has been drilled out and a new, smaller, tan plastic case with silver primer inserted in the new opening, ala’ the 9mm SMAW cartridge case design. There are no case markings beyond the old and new headstamps.


It looks like that primer was electrically fired as it it not dented by a firing pin but the case is fired. The ring of plastic also makes me think electrical. Sorry I can’t help you any further with ID.


The round looks like a 44 cal blank inserted. I have these blanks with red, green, or yellow paint over primer. I do not know what the blanks are for. or if the color represents a different charge. Can you see a plastic case inside?


I googled the headstamp and got this:

“DE LA Mare Engineering Inc in San Fernando, CA is a private company categorized under Services Allied To Motion Pictures. Our records show it was established in 1952 and incorporated in California. Current estimates show this company has an annual revenue of $2.5 to 5 million and employs a staff of approximately 10 to 19. Companies like DE LA Mare Engineering Inc usually offer: Battle Fogger, Area Fogger, Fan Misting System, Mist Systems and Mist Watering System.”

They must use the round/blank as some kind of tool or ignition system for movie effects.


The inserted cartridge is a 5-in-1 movie blank. A black plastic cased variation also exist.


As Fede says, the insert is a 5-in-1 for the movie industry. I have them with about 15 different head colors. I have never found what the colors mean. The cases are supplied as New Primed or Unprimed Empties. Each Armorer for each movie probably has his own color code. My guess is that the .50 BMG is a movie special effects round. Using the 5-in-1 insert would be a cheap and easy way to make a lot of different special effect .50 BMG’s.


thanks for the leads everyone.

Yes, I’m familar with the 5 in 1 blanks, have many of them myself, but they were unheadstamped.

I can’t see anything inside the case, but a slight protrusion of whatever case this originally was before being fired.

I had googled De La Mare, but only came up with a reference to a company in Luxemborg.

appreciate the tips !