Canadian Navy 18 Pounder by MAC

[Falcon]

I recently got an 18 Pounder case that I believe to be Canadian. It is also interesting as it has an "N" stamped near the calibre marking, indicating naval use. It is also interesting isn that it has the full date (15th July 1916). I also have a canadian 2 Pounder case with the full date.

The headstamp is:

12 O'Clock:

18 PR. N
II

3 O'Clock:

M.A.C.
237P

6 O'Clock

1916

9 O'Clock: (writing is tilted at 90 degrees to rest of H/S.

B_A
15 7 16
/|\ in "C"

Who was "M.A.C."? and what was the 18 Pounder used for in Naval Terms?

Any info would be helpful.

 

[Mathias]

Hello,

I have a similar cartridge case.
M.A.C. is told me to be MacFarlane Electrical Co., London and B.A. is not known.
I don't think the N stands for Naval here.

A photo of my similar 18 pounder cartridge case:

Mathias

 

[Falcon]

I was also told that, but then thought it might be Canadian due to the markings (broad arrow nside a "C"), however, I could be wrong.