I think it’s a blank anyway
On the left
Obviously a Norwegain made one by Bakelittfabrikken.
Pack Howitzer M1?
Made for US M101 howitzers in Norwegian service.
M101 is 105mm. This says 75mm.
Yes, but the Norwegian guns were converted to 75 mm for this purpose.
I found this on Wikipedia
Two M2 howitzers (1942) are still employed in providing the gun salute at Kristiansten Fortress, in Trondheim, Norway. M101/M2 is one of three approved salute guns in the Norwegian armed forces, and have been reduced to a caliber of 75 millimetres (3.0 in) for this purpose. They are used for gun salute also at Rena and Setermoen.