23 x 139 mystery

[SG500]

Can anyone help me out with identifying this one please.
Case length 139mm
Calibre 23mm
Rim diameter approximately 28mm
Steel case.
No markings apart from a small diamond on the projectile

Its not any of the .90 cal T series which have the same case length.

There is a Hispano and an AMRON listed with the same case dimensions.

Anyone familiar with this one and know what it is?

All INERT etc.

Thanks.

Dave.

 

[charley777]

Dave....the Amron 23x139 is the central case in the first photo.
the other photos show what i think are the Hispano 23x139.
perhaps you can study the base/groove/rim proportions....i suspect your round is the Hispano...

 

[SG500]

View attachment 60796View attachment 60797View attachment 60798Dave....the Amron 23x139 is the central case in the first photo.
the other photos show what i think are the Hispano 23x139.
perhaps you can study the base/groove/rim proportions....i suspect your round is the Hispano...

Thanks Charley, some nice rounds there especially the 40mm.
Dave.

 

[Bob Gerber]

The depicted cartridge is a 23mm x 139 HS 823. This cartridge/weapon appears in 1955 and carries the designation “820 AB”. The idea was to increase the lethality by enlarging the caliber without diminishing the rate of fire or augmenting the weight of the gun. For instance, the explosive content of the HE shell was almost doubled from 11g to 20g compared with the 20mm x 139 HS 820 ammunition. The original conical projectile point was abandoned in favor of an ogive with relatively large radius. The original copper rotating band appears to have been replaced by one made of sintered iron. As far as I know, based on construction drawings, the development of this ammunition ended around 1965. The HS 823 system remained experimental.

Bob Gerber

 

[SG500]

Thanks Bob, appreciated.
Dave.