Need information on experimental 30 mm case based on 2 pounder

[Hoeksel]

I found this strange case, that is documented in a list of case dimensions. In addition, I have seen it before. The headstamp is of a normal 2 pounder case No2.

Dimensions are ~ 30x319DR56,8 (so longer than a 2 pounder case which is 304 mm). The neck is ~153 mm long. The primer is the same as for the 2 pounder case.

Anybody have information on it? My main question besides if original, is it WW2?

 

[Bob7.62W]

The date appears to be 1942 in the 6 o'clock position, which is where the date is on the 2 pdrs in my collection. Other than that, this is a new one on me!