Help with 20mm Oerlikon Projectile ID

[LarryF264]

Hello All, this is only my second post on BOCN, but I hope someone can help with the ID of this projectile.

I think the projectile is an Oerlikon due to the narrow driving band (4.3mm wide and is close to another Canadian Oe that I have). It is stuffed into a Canadian 20x110 Hispano case (headstamped DAC 20MM 45 with a broad arrow /|\ inside the C, so Dominion Arsenal I believe).

I also found a note from Bill Woodin in the IAA Journal (#365) that US 20mm Oerlikon BL&P projectiles without tracer measure about 52.6mm (2.07") from the front edge of the driving band to the joint for the fuze, which matches the one I have. He also says tracer projectiles, such as HEI-T are shorter, measuring about 50mm (1.97") for the same distance.

The "fuze" is steel without any markings that I can see. Is this a dummy nose cap?

If it has a dummy nose cap, would this dark green projectile be a BL&P or TP projectile? I've seen several colors of dark green at least for US Navy projectiles, but green could mean HEI-T (at least for Canada and Britain). Which do you think it is?

I read in another BOCN post that 20mm rounds were made in Canada under contract for the US Navy and (if in the original case) would be identified by the headstamp looking like a US one (maker code, 20 MM MK-II, 4-digit year) rather than a UK headstamp (maker code, 20 MM, 2-digit year). Do I have this correct? I have one example of each - the DAC case shown below and a 20mm Oe made at Three Rivers (TR) with a US style headstamp (TR 20 MM MK-II 1944).

In this case if the projectile is not original to the case (which appears very likely to me), then I think it is at least possible that it was made under contract by a Canadian arsenal for the US Navy (assuming I got this info right). The color seems to match one that US-Subs posted in the Bombatorium thread (Jeff's photo is below), but there were no details on his round. I also found another Canadian Oe round on the IAA forum that looked like the same color (but again no details on the projectile).

Photos of my projectile and Hispano case:

And Jeff's photo below from the Bombatorium thread with his 20mm Oe in the center with a similar color projectile:

Thanks and any help is much appreciated!

-Larry

 

[ron3350]

Larry
I think you are correct and have an inert Oerlikon projectile stuffed into a Hispano case. It would need extra mouth crimping due to the smaller base.
Oerlikon projectiles are 18.9 - 19mm diameter below the 4mm drive band and the body is 19.6mm and 20mm at the swelled top.
Hispano projectiles are 19.5mm below the drive band and the body is 19.9-20mm with no swelling.

I note 2 heavy stabs on fuzes of brown USA dummy Oe rounds.
I note 4 stabs on UK Hispano SAPIR with dummy fuzes to stop them unthreading.
I hope this helps you.

 

[LarryF264]

Ron, thank you. This is very helpful and seems to fit.

My green projectile is loose in the case, which makes sense with the smaller base diameter. The crimp seems to prevent it from being removed from the Hispano case by hand, so I'll have to find a way to coax it out without causing damage to the cartridge or me. Body measurements are 19.5mm and 19.9mm at the swell, which seems reasonable for the Oerlikon measurements you gave.

I should have also noted that it has 4 stabs holding the dummy fuze in place, which might be consistent with being made in Canada.

 

[rigby]

I also found a note from Bill Woodin in the IAA Journal (#365) that US 20mm Oerlikon BL&P projectiles without tracer measure about 52.6mm (2.07") from the front edge of the driving band to the joint for the fuze, which matches the one I have. He also says tracer projectiles, such as HEI-T are shorter, measuring about 50mm (1.97") for the same distance.

I also have an American 20x110 RR Oerlikon with green bullet (BL&P).
This one also has four crimps that hold the fuse.
The bullet is stamped "MK.3 F 3 -43 Y.A."
The dimensions are the same as described above...52.6mmm from driving band to fuse.

 

[LarryF264]

Thanks Rigby, nice specimen and that ads a bit more to my understanding.

So I'm not sure if my projectile was made in the US or Canada for the US Navy, but it certainly looks close to yours other than the stamps (mine has no visible markings, but I need to get my magnifier to be sure).

Does yours have a steel dummy fuze?

I also read in that same IAA journal that Bill Woodin said the American BL&P would be stamped "MK 3" so this fits with yours.

Regardless of where mine was made, at least I can be confident that it is inert.