Primer Seal Colors

OK, it’s Sunday, the AZ Cardinals are up by 24 points, I’m bored.

So let’s talk about something I’ve not seen discussed before. The colors used for a primer seal.

I’m primarily a US Military guy so what little knowledge I have on the subject is confined to those cartridges. I know that there are instances where the color identifies a particular load that would otherwise be indistinguishable once removed from the box, but, disregarding those, does the color on the typical, common cartridge mean anything? When did the practice of color sealing the primer first start? How many colors are there? I have seen black, red, blue, purple, green, and yellow, with red seemingly the most common. Are there other colors? Why are some sealed and others not? Is there any relationship between what the US uses and what are common in other countries?

Maybe the start of an interesting thread or maybe a dead end.


Here is the basic information on primer seal colour on British Serivce Ammuniton:

Purple: Ball
Green: AP and Semi AP
Blue: Incendiary
Red: Tracer
Yellow: Proof and Ballistic Standard
Black: Observing and Explosive
Clear: Blank

The colour of the primer seal to identify the loading was standardised in 1926, and used until the advent of NATO standard rounds in British service. However, purple for ball and red for tracer are still found today on British made ammunition. As far as I know, the UK was one of the only countries to do this rather than colour tips for identofying most of the projectile types of small arms rounds.

I think we have discussed the US primer seals before. With few exceptions as far as I know, the color of the primer seals on U.S. Military small arms ammunition are meaningless of themselves. I have found, for example, 5.56 ammunition from the same lots of LC ammunition, in the same boxes, with three differenct colors of seals - red, green and purple, again, all in the same box of 20. To tell you the truth, I said “with few exceptions,” but off hand, aside from proof loads with all red bases, where it is hard to tell the primer seal color if there is any separate primer seal, I can’t think, off hand, of any exceptions.


Although I suppose one could argue that theT275 International Match is not military ammunition (I would argue that it IS), the different loads are identified by the primer seal color. Green, blue, black and red to be specific. I have also noticed that the cartridges loaded with the FA34 primer seem to have a black seal.

But other than those examples I cannot name any that are unique. Maybe I’ll get resposnses from others who may know of other examples.


Ray - could be. I don’t even know what those international match loads are, who made them, for what purpose and when. I assume they are 7.62 x 51.

I’d concur with most of what’s been said on the subject, with a few footnotes. US Military ammunition, generally, no significance to the primer sealant code, but some notable exceptions. US military almost always specifies a sealant, very rare that I’ve encountered any that didn’t have a sealant. My experience, however, being with the big .50 caliber, is that purple is the more prevalent color. 5.56 & 7.62 seems to be popular in red. To the color list, I’d add clear and an olive drab that I have seen on some .50 caliber versions. To REALLY stir up some confusion is the assortment of .50 caliber ammunition now coming out of the Lake City Army Ammunition Plant, a whole HOST of new colors, as illustrated here. ALL of these rounds came from the same lot.

(pic is approx 400k) … Colors.jpg

Left to Right, Top to Bottom:
Dark Violet Opaque, Red Transparent, White Opaque, Lavendar Opaque, Green Transparent, Pink Opaque, Purple Transparent, Mint Green Opaque.


The International Match ammunition (T275) was made by Frankford Arsenal for International Match competition, as one might presume. It is 7.62x51 NATO. The different primer colors identify the load (different velocities for different distances and positions). In 1960 it became the XM118 and in 1964 it was designated the M118 NM.


Wow! Those are some interesting colors. They look like the colors in a “paint by number” kit. ;>) ;>)


I’m gonna eat a couple of my own words. I said that most FA34 primers had a black seal. Well, the 7.62x51 NATO Tracer M62 apparantly has an No 34 primer and they have a red seal. So much for that theory.


Really interesting thread 4 sure! Awesome pictures of those 50’s Keith! Has anyone ever seen a multi colored sealant? Just curious.

Don’t forget the Germans used a color coding system as well in 7.92x57 Mauser:

Red PA color: AP core
Green: lead-cored ball
Blue (and variations): an iron (i.e. non-hardened) core (“SmE”)
Black: Observation or incendiary

Also, Japan, but only for 7.7mm (.303) Navy MG ammo:
Black: Ball
White: AP
Red: Tracer
Green: Incendiary
Explosive: Purple

The big problem with this system is visual recognition. It’s much easier to scan a belt of ammo and look for tip colors than it is to scan the butt-end of cartridges and look for PA colors. I don’t think any modern armies still use PA color codes, although I could be wrong.

It’s even more complicated than that.

Match ammunition is specialized stuff, and during that time the US teams didn’t really know what would work the best. Different lots were tried with different types of primers, different types of bullets, and different seating depths to the bullets as well. And different powders, if I recall.

Somewhere I have notes on a bunch of different T275’s that I pulled that came out of boxes. Some had flat primers, some had round; some had cambered pockets, others did not; bullet seating depths varied. Unfortunately I can’t put my hands on those notes right away.

In general the PA color on US ammunition (all calibers) after 1941 has no significance - the T275 7.62x51 match cartridge being the big exception.

When did the practice of color sealing the primer first start?

Although as Falcon stated, the British colour codes were standardised in 1926, they were first used in 1918.

The original proposal used black for Mark VII ball and purple for VIIz ball, but this was thought too complicated and purple became the colour for all ball rounds.

I have both red tracer and green AP p.a.s on 1918 dated rounds.



I would very much like to get your notes on the T275 cartridges when/if you find them.

AFAIK there were 3 variations, the T275, T275E1, and T275E2. The two primers used were the FA26 which was rounded and the FA34 which was the flat brass primer used at the end of T275 production and for other Match cartridges from then on. The bullets were basically BT 172 grain weight but there was some minor weight variations. I have not noticed any significant differences in seating depth. The cartridges slated for use at the Olympics were selected for best accuracy and were identified by a red primer seal color.

Of course, when the world changed and International and Olympic shooting meant air rifles and 22 rf, there was no longer a need for the specialized cartridges and they evolved into the common, plain vanilla, M118 NM.


Primer lacquering was initially introduced for a specific Purpose, during WW I…to Waterproof the ammunition. The colour coding was a subsidiary matter, and was handy for the machine gunner, who could see the belt (cartridge bases) from behind his gun (Maxim or Vickers or Hotchkiss) to tell what types of rounds were in the belt.

Those countries which did not colour code their ammo primers, still used coloured lacquers to be able to ascertain, at Quality inspection, that the ammo have been correctly waterproofed, and so any colour would do for the US and other countries (who mostly used red or black lacquers). The “tip colours” for “special” ammo came into vogue in the 1920s, to ID ammo with "common "primer seals. (hence the US, and a lot of FN “export” ammo was Tip coloured, to ID special loads.)

With the end of WWII, the “primer colour code” was more or less abandoned, and for most “Nato” ammo producers, a Purplish colour was generally used. The Germans still used Green for Ball, and Red for “Tracer”
(old habits die hard)…one can tell if German technical assistance has been in place with a lot of African and Asian makers of 7,62x51…besides the obvious characteristics of case manufacture, the Primer seals are green or red…just like the German ammo. (seen on Nigerian, Indonesian and Iranian ammo ( 7,62).
Some makers use colour codes to distinguish corrosive from noncorrosive priming (Yugoslavia/Former republics there-of), such as Red for Corr.,Green for Noncorr;
The Chinese use lacquers with abandon, even “clear” ones at times, but these usually match the neck seals as to colours…a common feature of all ComBloc ammo. Ammo type is usually Tip coded.

So what was originally a moisture proofing, turned out to be an ID process by some, and immaterial to others; and just as several contradictory systems developed, it all regressed after WW II to Point coding.
Except in the specific cases mentioned above.

One thing I have noticed with US M1909-style Open-neck-wadded blanks (any calibre) the Wad colour is red, and the primer seal is red ( unless the cases are from “pulled down ball”, then the primer may be black sealed.).
Even the M200 5,56 and the M82 7,62 Blanks are red primer sealed ( the latest "crimped " 7,62 is dark sealed at the point.)

Radway Green L10A2 7,62 blanks are either Green or Wine Red Point-crimp lacquered, but dark or plain lacquered primers.( 1960s dates).

Ah, the variety and mystery of coulered lacquers on cartridge cases.

Doc AV
AV Ballistics

Doc, can you post any photos of a green sealed RG 7.62 L10A2 blank? I have only ever seen red. L13A1 blanks are definitely green sealed.


Great information!

And some new collectors complain that there are no longer any specialties where they can break ground. ;) ;)


The L10A2 blank was initially clear lacquered (or at lease, some were as I did have a few of these years ago). Then the red type appeared for a while before being changed to green. I was told (by whom?) that the red was discontinued to avoid possible confusion with tracer.gravelbelly

I typed the above (mis)information from defective memory. Now that I have checked my old 7.62 files I see that I had a red lacquered tip headstamped: RG 63 L10.A2; a clear (uncoloured) one headstamped: RG 66 L.10.A2 and green tipped ones with the same 1966 headstamp. I stopped collecting this calibre years ago and no longer have these specimens. Initially I thought that the clear lacquered ones (I had a few) had simply missed the waterproofing process. But, as the brass slowly tarnished the lacquered tip stayed bright. A close look with a lens showed the lacquer was indeed in place.