Possibly unknown .303 inner case marking

Has anyone ever seen an “L” marking between the flash holes on the inside of a .303 case?

I found this marking yesterday on a case headstamped “GB 56 7”. The round itself is nothing out of the ordinary, a standard mark 7 ball round with a GM jacket and lead core.

This means there is possibly a previously unkonwn manufacturer of .303 cases. Any information or possible thoughts on who the manufacturercould be would be welcome.

Falcon –

According to Labbett & Mead’s “.303 Inch”, p.203, the internal case marking “L” was allocated to Greenwood & Batley.

Admittedly this is a bit confusing, because all the other marks they illustrate correspond fairly logically with the manufacturers:

So it has been seen before. I have Tony Edwards’ book on .303, it wasn’t listen in there. I really need to get a copy of Labbett and Mead’s .303 book, where would I get one?

You need to do a lot of searching on the internet auctions, and book stores.

It took me 3 years to find an affordable copy. There are 3 copies listed here: bookfinder.com/search/?ac=sl … 520service

Mea Culpa!

I missed this code in the list in my book, as I also did not list the folowing;
B ROF Blackpole
H ROF Hirwaun
C Crompton Parkinson, Doncaster
P Crompton Parkinson, Guisley

The omission of “L” was my error, but the others, although allocated, I have never seen.

The use of these internal stamps is still unclear, in that they appear in some batches and not others. Also they seem to appear in the wrong headstamps. For example, ROF Blackpole which was supposed to manufacture cases for filling at Swynnerton, appears with both the “R” for Radway Green and “4” for Kynoch, but I have never seen a “B”. Similarly for ROF Hirwaun.

Even the “L” only appears in post war GB production.

I will correct the next edition of my headstamp book.


Falcon, You can order it from the local Library. It takes a while to get it in but it is available, I have borrowed it several times. Then keep renewing it.

With modern scanner technology you can convert it all to disk.