"O" or "0" on FA primer


Sir Joost just started a thread on a 303 Drill round. John M answered and said this, in part:

The small “O” on the primer indicates and inert primer cup. It is not to be confused with the pre-WWII “O” marking on RWS non-corrosisive (Sinoxid) primers, nor on the Remington primers with “O” on the cup meant for commercial reloaders.

So, what is the meaning of the “O” or “0” on the FA 46 pre-NATO T65???


Aluminum cased unknown

I answered this a little while ago. guess I punched the wrong button, because my answer isn’t there. If it is some other thread, my fault, I guess.

I don’t have any real clue to why the FA primers had an “O” on them. the simple guess would be that they bought the primers from Remington for some reason. As I recall, the ones on the rounds your talking about have nickeled cups, which are not the norm for FA primers. I am not sure they had nickeled cups - I had one or two of these years ago and that’s what I remember. Other than that possibility, no clue. Yes, we do desparately need Volume III of HWS.



All of my FA pre-NATO rounds have nickeled cups, as does the first FA NATO, FA+55. On the other hand, the first LC production of the T65, LC54, and the first LC NATO, LC+55 have brass cups.

I also have an FA 46 with a rounded nickel cup but without the “0”.



Does anyone have a photo of:

“Remington primers with “O” on the cup meant for commercial reloaders.”



Ray - I will try to scan one and see if it comes out.



I can confirm that in the early 1970s Lake City made their own cups. I visited them and was told the story of the guy down cleaning out a pan used in the primer filling facility. They have no idea what happened but there was a Bang and he was dismembered and dead down in the bunker where they cleaned the equipment from the primer facility. They called it a bunker but I didn’t see it. Anyway, no doubt about LC being in the primer business and probably were for many years.

Cheers, Lew


Ray had a great idea in wanting to look at the “0” Remington primers. I don’t have a dupe of any of the FA rounds with “0” primer for comparison, and they could be completely different. As you can see from the picture of three different 7.65 Para blanks, probably loaded by Stembridge Gun Room for cinema use, the character is actually a large Zero rather than the more rounded letter “O.” Hope this picture can provide an answer.

John Moss



That certainly looks like it, and answers the question.

But every answer seems to bring with it other questions.

Why would FA use the Remington primer? Why only in 1946? And why only for some of the 46 production?

Maybe 46 was the year of primer experimentation. As I said I also have an FA 46 with a plain domed nickeled primer.



I have the same ‘0’ marked nickel primer on one of my FA 46 pre-NATO T65. In addition, all of mine with FA headstamps have nickel primers except one FA 49 which is brass. I have both brass and nickel LC 54 primers.



Interesting. I’ve not seen a pre-NATO FA brass primer.

This conversation caused me take a closer look at some of my cartridges, especially the FA 46 with the domed nickeled primer. It almost looks like a WCC product. At first it appears to have no primer seal. But when I look with a jewelers loupe there is some sort of seal. It appears to be clear except under certain light conditions it also appears to be a very faint green?

Maybe it and the Remington primer were part of some sort of primer test, after all. During the early years of the T65 they were testing all components, including the powder, and I suppose looking for the best primer to ignite ball powder would be important.

John, as far as you know were those Remington primers with the “0” any different than the ones they used for their own ammunition?

And what the heck does the “0” mean??

And why are we talking about stuff like this? If our wives ever find out they’ll put us in straight jackets. ;)




Ray - when I first encountered round with these primers (in fact, likely the ones I showed) I asked our Remington Rep to find out about it. I can’t say this is gospel. Sometimes the factories or their reps tell you anything just to get you off their backs. I have found they don’t like questions about their ammunition, for the most part. Regardless, I was told that the “O” was put on primers sent to other commercial houses (primarily commercial reloaders) so that should there be any trouble with the cartridges themselves, Remington could know that they were not a Remington-loaded product. For example, all of my .30 Luger blanks are, coincidentally, with REM-UMC headstamp, but they were not loaded as blanks by Remington. I don’t recall ever seeing these 'O" primers on primers offered in gun shops for sale to individual reloaders, but then I don’t know the time frame that Remington made these marked primers. I did not start in the gun industry until about late 1963.

Regarding the meaning of the “0” itself, I got no answer other than that it just was a symbol that was easily applied to the primer cup and had no special meaning as a letter or digit, but rather only signified what we were talking about, that it was not a primer Remington themselves put into any factory-loaded ammunition. Again, can’t vouch for the accuracy of that, but it is well known that while most things on cartridges represent some particular thing, the actual symbol used isn’t always the initial for any particular word or term. The CCI “A” primers are a good example of that. the “A” by itself, unlike the “B” for Benchrest on their primers, has no meaning standing alone.

I am sure that during the tests for the NATO cartridge, there was plenty of input from Civilian industry. Few of these cartridges originate solely in military arsenals. I think you are probably right about testing different primers, anyway. I would guess the domed primer, which I have seen on rounds, is Winchester as well. There was a question on the Forum recently about FA helmet test .45 rounds from WWI. Although Remington primed and headstamped cases were used, those rounds were actually loaded at Frankford Arsenal. That brings up the question why they didn’t use their own brass. Again, all of these arsenals get assistance from private industry, I’m sure in other fields of militaqry manufacture, not just ammunition.


Ooops. Now I have to fess up. I went out to the collection to get the brass primer FA 49 and the nickel primer LC 54 so I could get a photo and found I had made an error on both when cataloging them. So, please disregard my observations above; nickel FA primers and the brass LC primers are still a safe bet. All is still right in Ray’s world.



Phew! Now I’ll sleep better.

And it’s almost that time, BTW.

Just so everybody knows, I’m still looking for a WCC 54 and a steel FA 54 pre-NATO.



A number of the the early pre-nato in 47 & 49 mm case length boxes note use of a Remington primer on the label. (usually a plain white label with the blue colored duplicated typewritter print. Sorry I don’t remember exactly the name of the machine which used that method.) Not all, ofcourse, had an “0” in the primer.




Do you mean that there were other cartridges loaded with Remington primers without the “0”? Any way to ID them?



Mimeograph is probably correct.
No way to ID them other than the box label.
Just looked at 5 FA boxes & all say “PRIMER REMINGTON NO. 39” or a variation thereof. Some other boxes note PRIMER: Percussion No. 34 (or 36) without a manufacturers name.