headstamp is barely readable H on the 9 o’clock and 43 at 6 o’clock
It is a Swedish 20 x 145 R.
This reminds me of the swedish Tube-cannon Bofors M/40 20x145R
It has the same thick rim…
More dimensions would help, to secure this…
Peter, it is the same as described by Fede. It is the M40 case.
if you look on the time stamp you will see we published this at the same minute of time…
the case was actually found in Sweden, so it makes sense.