Question on 2 shells

[jozefb2009]

Hello,

Does anybody know what the below shell might have been used for?
It is 15,9cm in length and has a diameter of around 42mm. Why does it have the sloped edge on the rim?



Can anybody tell me the meaning of the letter A on the below shell, which is 10cm long and is 7,5cm in diameter?



Thanks,

Jf

 

[charley777]

Greetings
The first one looks like a Hotchkiss with the "sloped" rim. Is 42mm the diameter of the base? or the neck?
The second one...is 7,5cm the base diameter or the neck diameter? Sorry, i do not know the meaning of the "A".
Thanks, Charley