Help/info/ideas needed!!

[hicky1300]

Hi all
Picked up this case today. I realise it is a 37mm M16 case but the headstamp had me intrigued - hence why I bought it!
The headstamp is onl! CF (Cordite Full I assume?) at the 6 o`clock position with a + at about 1 o`clock & that is all
Primer appears unstruck & unfired and has the stencil marks A-F M 179V40 around it. I assume (again the 40 is 1940?).
Also the cap now has me thinking. When I first saw it I thought it was just some gash brass cap that had been put on.
The cap though has exactly the same level of patina/dulling as the rest of the case & the cap is a perfect fit & very well made.

Is this a british or commonwealth mad case & what is the cap/top & does it belong with the case?

Cheers

 

[HAZORD]

No idea regarding the cap, and the primer doesn't look U.S, but FYI, the U.S. used high pressure sealed primers in all of their cases 37mm and larger. The center part that you see is actually captured in a bore so it can travel forward when the firing pin hits it. The opposite side of the part in the middle has a firing pin on it. This false firing pin is free to travel forward and strikes a primer underneath when it is slammed forward by the weapon firing pin. The primer ignites the main charge, and if the pressure is so great as to pierce the primer, the gas is contained by the false firing pin.

Therefore all of the U.S. WWII and newer large caliber primers look like they are unfired.

 

[Hoeksel]

CF indeed points out it is used by the commonwealth. I have a few CF stamped cases. My cases are US made and I think yours is as well. The cap I have not seen before.