4,7 inch Shell casing headstamps question.

[Michel]

This one saw the light of day after a lot a years on the bottom of the sea. After looking at the stamp I was wondering that they used a lot of asterix marks I was once told a asterix mark was used after a modification? But what can be modified at a shell casing.. recalibreathed? There is also a F mark with a line through it canceling it combined with 2 stamped point marks, fired 3 times? And 2 small marks in a square SQ and GR meaning? A lot of questions but maybe some one could enlighten me.

 

[Vasco Da Gama]

Afternoon Michel
I would read the markings as the guns that the case would be suitable for, I can see that the case would be for Mk9, Mk12 and Mk12 star guns. The modification is for the gun and not to the shell case. I don' t have a reference to hand but you should be able to find out that the Mk12 gun was modified at some point and this explains why the markings have been added later and post original manufacture of the case. Interesting that the primer protector is still in place, would this indicate that the round was never used and fell over the side or that the round went to the bottom with the ship!

 

[Michel]

Vasco, your solution to the asterix question sounds correct, a bit of research gave me. Mark XI ** (difficult to see on the pic) means Denoted differences in breech ring for the CPXVIII mounting. Perfect thanks.
Anymore for the other questions especially the F (fired?) and centre points.

 

[2pounder]

F is for full charge. what looks like II below the gun types is the case mark no. they do have minor changes like thickness of the base which raises the Mk. No. do you know what ship did it come from? as not many had Mk IX and IX* guns in 1937 when the case was made. Unfortueatley the zinchas leached out of the brass to leave it very coppery, nothing can be done about that. Yes the domed centre cover is over a primer it might be worth carefully trying to lift it, its a sprung fit in three equispaced holes. Keep us posted.

 

[Michel]

Thanks 2pounder, you gave me the remaining answers. Of course it was one of the first things I did, to lift the primer cover so here a pic. Nice there is a pull tab that would have been run thru the cover.