20mm Cannon Rounds

[oktato]

Hi,

Can anyone help with more information on these two 20mm cannon rounds?

The case length on the drill round is approx. 142mm but I guess this is designed to include the rifling band. The projectile is engraved: "20K DM20 LOS DN-3-6"

The rim is rebated with a diameter of approx. 25mm.

I couldn't see this round on Anthony Williams' Guide to collecting 20mm cannon ammunition. Am I right in thinking it is 20x139mm? And can I ask what cannon it is designed for?

The case length on the round with the crimped projectile is 139mm. The head stamp is "20x139 DM1323A1 LOS NWM 97K4257"

The person I bought this from thought it was his best round. Am I right in thinking it is a canister round? And does anyone have a diagram of this round.

Thanks in advance for any help!

Gary

 

[tomsk]

The first one is a 20x139 drill the second is a 20x139 blank from the netherlands hope this helps
Regards
Tomsk

 

[oktato]

Hi Tomsk,

Thanks for your comments.

I'm a bit surprised that the drill round has a rebated rim whereas the usual 20x139 is rimless, but not rebated. Is it normal for 20x139mm drill rounds to have a rebated rim?

I'm also surprised that the blank round has a separate projectile. I know that break-up rounds have a plastic projectile which is designed to break up after leaving the barrel but, in this case, the metal projectile would be dangerous - that's why I thought it might be a canister round.

Any diagrams would be a great help.

Cheers,

Gary

 

[rigby]

The blank cartridge is used with a special blank cartridge device, in which the bullet is pushed into the case as it is fed in.
Left before firing, right after firing.

 

[rigby]

I also have two DM20 dummies, one rimless and one with rebated rim.
But I don't have an explanation for that yet.