20x110RB Oerlikon - US headstamp question


I have been asked about a headstamp on an Oerlikon case, stated to be US-made. It reads as follows:

152 B (in a diamond) 41.

The 41 is easy enough to interpret, but can anyone provide information about the 152 and the symbol?



I do not know if your case is American or not but B in diamond is in the British listings as Baker Engineering Co., Auburn, New South Wales. They certainly produced ordnance related articles but whether they ever made cases I do not know.




There is almost no doubt about your B in a diamond logo on a 20x110 Oe case:

If it is a small B letter raised in a slightly excavated diamond, it was the trade mark of BRIDGEPORT BRASS Co, in Bridgeport CT.(USA).

This hstp is usually found on 20 mm Oe of WW II production from the years 1941 to 1945.
Also on some experimental ammo, I have, for instance in collection a .50" High Velocity with this logo.



Thanks gentlemen!

  • As it is mentioned above, the headstamp mark stands for “Bridgeport Brass Co.”, Bridgeport [CT], USA. This company also used as a maker’s mark the letter “B” inside of a circle or the letters “BBC”. This company manufactured 20mm Hispano rimless [20X110] ammo with brass shell cases too, not only 20mm Oerlikon “S” ammo [20X110RB] with brass shell cases. — The headstamp for the 20X110RB round mentioned first by Tony Williams, “152 41”, is typical for the rounds manufactured in 1941-42. Starting already with the year 1942, the headstamp for the 20X110RB rounds made by “Bridgeport Brass Co.” shows " 1942" [or 1943, 1944, 1945] over “20MM MK-2” [or “20MM MK-4”]. Liviu 03/17/07

  • For an unknown reason, when I posted above, the mark cannot be seen. I hope my lines will be understood. Liviu 03/17/07

  • It seems that the symbols which look like the letter “V” horizontal with the letter “B” in between [to show the diamond frame] cannot be posted here. Liviu 03/17/07