Need help identifying plus... is it safe?

Hi there!

My grandmother handed me this shell and said “Your grandfather brought this back from D-Day.”

I think it’s still live!?!?!

He was in the Merchant Marines during D-Day.

It’s a 20mm shell marked 1943. Has cardboard case.

3 questions:

  1. Is it safe to be in my house?
  2. Can you help me identify the exact bullet this is?
  3. What is the approximate worth, assuming it’s safe and legal?

I have more pics but it will only allow me to post one.

Thank you, all!


Hello Tifdotcom and wellcome to this Forum

According the story of your grandmother, it is quite possible this is a live round. Don’t panic but handle with care ( don’t drop it!). Very curious to me are the scratches on top of it. That maybe could mean the grenade has been discharged. Is it fastened to the case? I’m not that 20 mm specialist but according to some marks on it, it seems to be a British or American cartridge. Can you give the dimensions of the caselength and a picture of the headstamp, please? Without doubt, some other members of this Forum will identify this case at first glance.

1 Like

Could only post one pic with the post, but have more. On green part, it’s marked MK-3-32H9-43. On brass casing, it’s marked ZG22SJ43 and under it, SPDN4327. Bottom only has 20m.m.-MK-2, 1943, and what looks like a B with a circle around it. Measurements are 7.25” or 18cm.

It’s fastened to the case, but wobbly.

Looks to me like someone has had it apart, as the projectile isn’t seated properly, and the mouth of the casing is ‘belled’. There is also no primer. Also, I think black is for AP (?).

Best regards,


Hi Simon,
Bullet itself is dark green. Might not come across in pic. It’s not well-fastened. It’s wobbly. Didn’t want to play with it. 😀

Thx for your response duqjans! Hoping to get to the bottom of it. Will be careful handling. 😀


Welcome to the forum.

I thinking this this is “ball, practice or blind loaded” projectile from a 20x110mm Hispano (possibly post WW2) that has been placed in a 20x110mmRB (Rebated Rim) Oerlikon cartridge case. The cartridge case has no primer and was produced by Bridgeport Brass Co., Bridgeport Conn. in 1943. The Mk-2 refers to this being a slightly modified cartridge case.

Below is an enlarged section of one of your photos.

Can you read and list here the letters and numbers showing at the red & green arrow?

Also note at the red & blue arrow how the cartridge case neck has been stretched/bent, possibly by pulling the projectile originally to the cartridge case or inserting a projectile into the case.


Hi Brian,

Thanks for the kind welcome.

Answers here on markings:


Excellent! Sorry I missed your earlier post with the information.

So to correct what I said in my earlier post and add additional information-

The stencil mark on the cartridge case ZG22SJ43, ZG = Blind Loaded & Plugged (BL & P) cartridge (NO explosive material and NO tracer).

SJ43 = U.S. Navy loading facility St. Julians, 1943.

Black paint on the projectile indicates , with this type of projectile, a BALL projectile (contains NO explosives or tracer element) which goes along with this being a BL & P cartridge.

The MK-3-32H9-43 identifies the projectile as a MK3 projectile (with false nose fuze) manufactured in 1943.

The projectile in the case is probably original to the case.

From the headstamp (stamped markings on the bottom of the cartridge case) the B in a circle indicates the cartridge case maker Bridgeport Brass Co., Bridgeport Conn.

So what you have is a 20x110mmRB Oerlikon cartridge, practice loading, U.S. Navy, WW2. This type of cartridge was used for practice firing the Oerlikon gun.

Hope this helps.



This is so helpful. Thank you so much! Great to know it doesn’t have explosives in it. Whew!!!

Thank you so much for that detailed info. Really appreciate your time and interest.

Thanks again and have a great week!




Just re-reading your response. The projectile is actually painted dark green, not black. The pic might just be dark. Does that change anything?

Thank you!


No, that does not change anything. One source I have shows a black projectile while a WW2 period color chart shown below indicates dark green for practice projectiles (BL & P).



Very well done indeed! About value? I don’t think this cartridge had great value in $. But keep it as a lasting souvenir to your grandfather.

Yes wasn’t planning on selling, but was curious. Thank you so much for your help!! Really appreciate this forum.