L70 Bofors unusual headstamp

[Rrickoshae]

Please see the attached photos of an L70 Bofors headstamp. It would appear to have been used in trials, the numbers 173 over 72004 having been crossed out and on the opposite side 173 over 76001 added. Can anyone add anything more about the possible use this case was put to?

The second photo shows more clearly that the breech appears to have closed before the case was fully seated in the chamber

many thanks, Dave

 

[ron3350]

Here is my opinion but we both need confirmation on the markings.

173 is Bofors AB, Sweden. 72004 is 1972 Lot 4.
583 72 - 002 means the case was imported to Sweden from Raufoss, Norway. 1972 Lot 2.
173 76001 is possibly the loading date or reloaded in 1976 Lot 1.