American 20mm Hispano

The pictures show and American 20mm Hispano with an odd projectile. The case is H/s ‘20MM M21A1 STON 53’ and has an unusual crimp. The projectile appears to have had some sort of plastic covering which has been stripped off in the centre section. The bottom of the projectile is glued into what seems to be a wide driving band. My first thoughts are that this is a home made projectile. Can anyone help please?

I am not sure what it is with the irregular shape in the area where the white centre is joining the ogive but in general this appears to be a “break up” projectile as we know it from NWM/DAG.

These do exist in a couple of variants (including experimental) and were developed/used with several calibers.

Looks like a damaged '70’s/80’s vintage break-up projectile used as a ‘stuffer’ in a fired '50’s case. The crimp would be deeper in an unfired round.

Thanks EOD. Takapu, it is, or at least was ,in a loaded case.