Unknown 6 inch (?) case

[RobertB]

Can anyone please assist in identifying this case:
case mouth diameter: 155-157mm
case length: 900mm
rim diameter: 184mm

 

[M8owner]

The ordnance bomb symbol makes me lean towards French manufacture.

 

[Burney Davis]

Your case is French Naval, 138.6mm model 1923. See the following link - http://www.navweaps.com/Weapons/WNFR_55-40_m1923.php.

D

 

[RobertB]

Would the text in the lower part of the headstamp indicate a date of manufacture?
MA.I.3.5.30
Perhaps the "30" is 1930?

 

[Michel]

That is correct 1930.