Odd case Cut down?

[hicky1300]

Hi All & Happy New Year.

Need help with this one please.
Unable to ID it & fairly sure it has (unfortunately) been cut down.
As someone/thing has beten the heck out of it there is no headstamp I can make out a `B` on there & the primer is stamped MK 19 - unable to find what cases used a MK19.
This was amongst a job lot of assorted brass & rounds & theres a few 1950`s 30mm Aden cases cut down!!
Initial thought this was a 2 pounder case but the rim is wrong.
Length 136mm. Dia at rim (neck) 39. Dia at extraction rim42mm.
Wrong size for 30mm Rarden & the extraction groove/rim is wrong


Cheers

 

[hangarman]

COW gun???

 

[Burney Davis]

Pictures are difficult to see for me (very small) but I don't think COW gun. The rim diameter for that is 46.7mm and it had a screw in primer, although the very early cases did have a button primer.

 

[SG500]

28 x 198 (1.1 inch USN)
Cut down........presumably.
Are you sure the Adens are cut down or are they the LV short cased version?
Dave.

 

[Hoeksel]

I am thinking what SG500 is thinking.

 

[Michel]

1.1 inch rimdiameter 42mm.