BM Cannon Shell Queries

I have some queries about BMARCO headstamped cannon shells in 20 and 25mm.
This company was owned by Oerlikon-Buhrle (1971-88).
Astra Holdings (1988-92) until it closed in 1992.
I also ask if BM actually made these steel cases at Grantham or imported them from Switzerland.

Most of the 1980-90 cases are green steel and have BM headstamps.
Projectiles are marked either BM or BMO. Is the O for Oerlikon?
I show two 25x137 Oe examples of TP loadings.

The 20x129 Oe is headstamped BM 286 85.
Is this APT projectile correct for this BM case? Seems to have pull marks on the band.
Projectile marked: TTT AP-T V-1-85.

20x129 Oe APT BM 286 85

Hi Ron,

“BMO” was the new identification symbol assignted to this manufacturer after Astra acquired BMARCo. The earliest and latest lots I have observed so far are 02-88 and 12-90.



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I wonder if Oerlikon (in Switzerland) ever made any medium caliber steel cases.

As we are on it; I have 2 entries on other codes they used.

  • BMR
  • BMRC

Is anybody able to confirm and is aware of time frames the codes were used?

I have never seen a BMO headstamp. For BM I have dates from 1973-1997 in my collection.

I also note BMO on primers in 30x170 Oe case from BM 96 .
Earlier primers were from SF .
Great information so far and thanks.

Hmm, when they were closed down in 1992 why do we see a 1996 headstamp here and a primer from 1997? And why BM and BMO, means BM should have been out after Astra took over?

The timeframe for “BMO” given above is under Astra management. In 1993, BMARco was purchased by ROF and moved to Nottingham. They used the same symbol until it was closed in 2002.

I assume that, like under the former management, they continued using “BM” for cases and “BMO” for assembled rounds, primers and tracer filler, but this is just speculation of my part.

Now I need info on the APT projectile. Maybe it is a “stuffer” but the dates match ?
Is this projectile found in other cases and from what country?

Ron, as almost all ammo I ever saw from BMARC was Oerlikon/Hispano designs your projectile seems to be correct.

Here an image from an Oerlikon flyer on 20x128.

The British Manufacturing & Research is rather complicated - the following is from Wikipedia, so normal caveats apply (that said, there are Hansard records which essentially verify it) -

"One of the arrangements came to light in 1995, regarding a company called BMARC. Previously owned by the Swiss arms manufacturer, Oerlikon, it was sold to the British Astra Holdings in May 1988. Apparently, Oerlikon continued as a partner in some transactions.

Astra executives and non-executive directors were well-connected to the British defense industry. It was not always clear, to the Government, if a project was being managed by BMARC, Astra, or, outside the UK, Oerlikon. “No one has yet mentioned that when the contract for that was signed the project was being handled by, and BMARC belonged to, Oerlikon, which is a Swiss company. It was not until nearly two years after that contract was entered into that the new management of Astra, headed by Mr. James, bought BMARC and continued with that contract. By 1988 the intelligence community realised that Oerlikon—not a British company—was exporting arms via Singapore to Iran but it did not specifically mention BMARC. His misfortune was that his very successful company, Astra, made two unfortunate purchases—BMARC and the other company that supplied the Iraqi gun, PRB.”

Because of the apparent continued involvement of Oerlikon after the sale, this might explain the continued use of the BM monogram.

However, there is no listing for BM after the sale

@Fede - Fede, What is your source that “BMO” was being used by ROF until 2002? The reason I ask is that a 2013 publication shows the monogram still assigned to Astra Defence Holdings.

@EOD - Alex, “BMR” was RNAD (Royal Navy Armaments Depot) Broughton Moor, Cumbria 1939 - 1963, then leased to Germany until 1977, then US navy until 1981 and finally NATO until 1992.
“BMRC” should be accompanied by “GM” and together with “BMARC” were WWII onwards monograms.

@ron3350 - Ron, “V” is Förenade Fabriksverken, Sweden.

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That does make sense as headstamps still BM but primers changed as mentioned from SF to BMO in the mid 90’s.

@TimG Hi Tim, I have the same list, but it is outdated by many years, because Astra and its subsidiaries was sold in 1992. Given that BMARC used “BMO” after being purchased by Astra, and later ROF purchased BMARC from the latter, in my opinion it is reasonable to assume that they continued using “BMO” until it was closed.

@cartridgecorner Curtis, I don’t understand what you mean regarding SF and BMO. Please, can you expand your explanation?



@Fede - Fede, a lot of monograms on that list are of stations/contractors that no longer exist e.g.
Bramley (Army School of Ammunition) BM/S - closed in 1974
Bramley (CAD) BML - closed in 1976
However, because of the statutory requirement regarding the storage and transportation of explosives and the high probability of encountering stores labelled by some nonextant stations/contractors, the list has to include their monograms. That said, one would expect to see an entry for ‘BM’ unless possibly the stores were all for foreign consumption.

BM cases are found with SF primers made from two different materials.

This one has SF and all the older ones do…The newer ones

The newer ones all have BMO on the primer marking like below

Curtis, yes, but why do you say it doesn’t make sense? The BMO marking appeared as early as 1988.

No I said or meant to say that makes sense. I agree

Oh, I misread your post, sorry!

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If my 20mm APT projectile is Swedish then what case should I fit to it? Who has one ?
If BM I assume it should have had BM on the projectile.
I do not think BM would use this projectile in their cases but maybe they did not design one for their 20x129 Oe and did use it?? This is the last bit I need to know. Thanks to all contributers.
It is probably too tight in the case to remove the projectile.