Identification of an early 37mm projectile

[US-Subs]

The rotating bands have me thinking French, the tapered base thinking a re-worked projectile for post WWI, perhaps for the 37x277R? You out there Gordon? There appears to be a 6-18 on the side, but a 31 on the base. I've never seen this style of nose.

 

[MINENAZ16]

British 1 1/2 Pr C.O.W. (nice one).

http://www.bocn.co.uk/vbforum/threa...-projectile?highlight=Coventry+Ordnance+Works