303 with knurled rim-what is it?

An IAA member without computer access has asked for identification of the following 303. The headstamp is SR 43 VIIIZ.

Any help appreciated.

SR= Royal Ordnance Factory,Aycliffe,United Kingdom (1940-1946)

I am not a .303 guy but is it possibly a high pressure test cartridge!!


All things are possible I suppose, but I doubt if it is a proof cartridge. The standard proof round for machine guns was the Proof Q Mark IV, although the Proof Q Mark III was also used. The identification of proof rounds was a coppered case.

It is only in comparatively recent times that the British military has adopted the knurled rim as an identification for proof rounds, with late examples of the 7.62mm L4A1 and 5.56mm proof rounds being marked in this way.

Having said that, I have no idea as to what it might be.


I’d sure like to see this round. I enlarged the closeup of the rim even larger, and it looks like there is a brass pin going thru the case above it. It could be just a mar, but it is a almost perfectly round “bright spot.” I wonder if it appears on the other side. Also, the inside of the rim looks funny, almost like it is a separate piece from the upper body of the case.

This is one place where having the cartridge case in hand would be superior to even the very decent pictures provided with this inquiry.


JJE’s response was pretty much what I was getting at. I’d also like to know if that “spot” that looks like a pin could be check out, to see if there is another directly oppoisite to it on the other side of the case.


The knurl is to unscrew the head (for some reason).
No evidence of a brass pin, but the head sure unscrew. Somebody put in a lot of work on this. Must have used two fired cases to make one. I wonder why???

The caselength with the head screwed on tight is 51.38mm. The heigth of the screw on head is 5.24mm and the threaded section is 3.39mm.

Would seem to be some nice machine work involved. If not some form of novelty item, perhaps a person with time and the tools sought an easier solution to de-capping Berdan primers?

Neat item for sure. Can’t wait to learn the “why?”.


I’m told that among other things .303 cases were made into cigarette lighters as a form of trench art. Has anyone ever seen one? I haven’t. It might be something of that sort here.

This is the only type of lighter I have in 303. I have a shotshell lighter that is all “internal”.

Nice bit of machining by somebody. I wonder how they held those bits of thin brass in the lathe without damaging them.

Lighters made from cartridge cases of one sort or another were popular during and after WW2, and 20mm cases were probably the commonest -I used to have one. But all those I have seen were “top loaders”, as filling through the base would require a very reliable ring-washer to prevent leakage.

If the base unscrews maybe the casemouth was meant to have a permanent stopper of some sort, perhaps a bullet should be fixed in? But what did it hold? Perhaps a bit of forensic analysis of the interior might help!

There are no signs of crimps on the neck of that case so I suspect that a later dated case was married up with the SR 43 head.


Perhaps some far-thinking machinist sat down one day and said; “Now how can I mess with the heads of a bunch of people 60 odd years from now?”

We’ll probably never know why he did this but its a shame he didn’t sign his work because he deserves recognition thru the ages. Could he even have imagined how much excitement he has stirred in otherwise logically stable minds?

Shotmeister, I have to seriously question your assertion above of “logically stable minds.” If that were so we wouldn’t be on this forum in the first place. I know how our wives (or ex-wives) would all vote.

Unless this item is unfinished, I can’t figure out why it would be used this way. The case is so thin, and most 303 chambers are so loose (I use to shoot and reload a lot of 303) that nobody in their right mind would try to load and fire this thing. If it had a bullet then you could hide something in it but then why knurl it.

Does anyone have anything similar???

I have a simmular case wich was given to me about 15 years ago. I came from a dutch gunsmith who died and several shell cases like this one were found while cleaning up the shop. The reason why the cases were changed like this never became clear.