Question on identical 65mm shell but with different rim diameter

[jozefb2009]

Hello,

I have 2 seamingly identical shells with the following measurements:
- length: 522mm
- diameter: 65mm

However both shells have a different rim diameter. On one shell the rim diameter is 88mm and on the other shell it is 94mm. Does anybody know why this is?



Thanks,

Jef

 

[Alpini]

The headstamps tell us that they are for different guns: Mle.1888-91 & Mle.1902.