Experimental US 57mm and others

[EODGUY]

I have these rounds in my collection. They are all US copies of WWII era German rounds.
The 57mm round with the rebatted rim was reportedly made for the T78 automatic 57mm gun, which was a copy of the German MK 112.
The T1 20x138mm Solothurn is shown next to a German round.
The T7 case I have both in an unheadstamped electric primed version and a percussion primed headstamped case. These are copies of the German MG-213.
I have been unable to find much information on the rounds/cases. Anyone out there have any reports or data?

 

[SG500]

Oh man, those are really nice rounds, excellent and thanks for showing them.
If you look at the attached link there's a 213/30 and a 213/20 just like yours.
Dave.

http://www.bocn.co.uk/vbforum/mauser-213-t27629.html?t=27629&highlight=mauser213

 

[Tony Williams]

I'd love one of those 57mm rounds, or even a case...

They were not actually 57mm, of course, as the German MK 112 aircraft gun fired 55x175B ammo and the US merely made some more ammo so they could test the German guns. I don't know why the US changed the nominal calibre.

Anyway, the guns were simply scaled-up versions of the 30mm MK 108 API blowback weapons. They were relatively light and fast-firing and were scheduled to be used in the anti-bomber role, but never made it into service. The HE shell weighed 1.485 kg and was fired at 600 m/s.

I believe that the nose cone of the shell was made from magnesium (at least in the German-made versions) which corrodes away quite quickly - I haven't seen a complete round, just the case and the main body of the projectile.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk