Jack, Please explain again why you are convinced this round is a 6.5mm Carcano.
I have done more careful measurements. First I measured some steel case rounds and found the difference between the bullet diameter and the casemouth diameter is about half a mm. When I measure the picture on my moniter the casemouth is 24mm. a 6.5mm bullet should yield a case mouth diameter of 7mm. That would make the image 3.43x (24 divided by 7). Multiplying 3.45 times 51mm, the case length would yield a case length on the image of 1.75mm. The actual image length would be slightly less because the case is at an angle. When I measure the image of the case, it is 152mm
If I assume the bullet diameter is 7.35mm then the casemouth diameter should be 7.85mm and the image on my monitor is 3.08x. This yields a case length of 156mm which is pretty close to the measured value on my monitor of 152mm, particularly when you consider that the angle of the case will slightly reduce the measured length on the image from the true length.
Bottom line is that I can’t see any way this case is a 6.5 Carcano and it sure seems to be a 7.35mm Carcano.
It is also interesting that the case is a black color while the 7.35mm steel case round pictured on the Italian website is clearly a brown lacquer.
Here is another photo the owner sent me which shows the black color pretty well.
I am reasonably convinced this is a 7.35mm Carcano but am open to a discussion on the point.
PS: I just remembered the 6.5 Carcano case length is 52 mm so the image length should have been slightly less than 178.3mm. This doesn’t change the argument above.