What company made this .303 round?

It looks to be a WWI made Mk seven ball, but who made it?. The base of the rim is marked at 12 o’clock “US 16”, 6 o’clock “VII”.

I believe it was US Ctg. Co., contract for UK before the US entered WWI.

I also have a 15 and a 17 with the rest of the HS the same. They are USCCo for Britain. Vic

Poor quality ammunition, mainly relegated to training in the UK.

Large amounts were supplied to the French who pulled it down and reloaded it as tracer, AP etc, usually adding four stake crimps to the primer for use in aircraft guns.


Thank you for the replies. It’s nice to know that we took such good care of our allies when it came to ammo.(?)
The round was found in more of the ammo I bought that is “battle field pick-up” from Navy Arms years ago. so far I’ve found some really interesting .303 rounds and oddities.

Rapid: The United States wasn’t allied with Great Britain in 1916 when that cartridge was produced. Jack

My reply was “tongue-in-cheek” as to the allies.
When I was active duty we would get ammo warnings about every quarter as to what was not serviceable any more. One that really sticks in my mind was that there was an 'Action required" teletype message that a lot ( as in number ) of 5"/54 UNIVERSAL full powder charges that would not chamber in the gun as they were too large in diameter. I had to check both magazines and report in writing that I did not have that lot number.This was in 1982.
In 1984 I was in Lima,Peru when the Naval Attache approached me and wanted to “beg” some powder charges off of my ship as his would not chamber in his ships guns. I met with him after work and sure enough, the powder lot number that had been recalled was sent to him as a NATO/Friendly Country for their use.
We really do take care of our Allies.( pun intended)

Rapid: I hope you kept a straight face when you realized which lot the Peruvian ship had been supplied with. It would, I think, avoid embarrassment on both sides and forestall a bunch of really awkward questions. This story also suggests that the breadth of “universal” is less than one might imagine! Jack

Getting back to the USCco 16 et al .303 ammo.

Britain began contracting supplies of all sorts of ordnance with US companies in late 1914. First ammo deliveries began in 1915, with Winchester (W) Remington (RA) and US Cartridge Co. (USCCo) delivering in that year.

The US, being Neutral, could sell to anybody. It was pure Commercialism, nothing to do with “Allies” ( until mid-1917); and the contracts were paid in Hard Cash (ie Gold)

There is still discussion whether the Winchester .303 order was made at the new Haven Plant or at the Western Cartridge Co. Plant in East Alton, Illinois.(This latter plant also made 7,62x54R for the Tsarist Gov’t at the same time).

Several problems immediately became evident…the Powder was of a type which deteriorated rapidly under adverse conditions, the Cases were then not annealed after forming ( leading to early “age/stress cracking” in the neck) and the Loading was erratic.
When the British gov’t supplied the French with .303 Lewis Guns and ammo for Airforce use, the French also found that the Uncrimped Boxer primers tended to back out of the cartridges on firing, causing Jams. Thus the French took the (US-made) Ammo, pulled it down, stab crimped the primed cases, and reloaded the ammo using either the original powder or their own (French made)Powder.
At the same time, they also used US cases to load “Specials” (Tracer, AP) with Projectiles supplied from Britain( Aerators “Sparklets” Ltd., Greenwood and Bately); imported British made MarkVIIz cases were also loaded in France.

Other US ammo remaining in Britain was relegated to Infantry training use, and not sent to the Western front.

At the end of the war, Britain found itself with Several Hundred Million rounds of US-made ammo which was found to be “not Optimum”. The worst was Dumped in the North Sea, along with quite a lot of Artillery Shells etc which had “Issues”. The remaineder was given away to the newly-formed Baltic States (Latvia, Lithuania and Estonia) all of which had some .303 guns in at least their “airforce” inventory, whilst Estonia also received large quantities of Obsolete .303 cal. Rifles ( Mostly MLE Mark I and I*). British contractors continued supplying the Baltic States well into the 1930s with both Rifle ammo and MG ammo for Air use.).

Portugal was the other big recipient of " discarded .303 ammo".

The Portuguese had sent a battalion to the Western front, where it was almost fully equipped by the British, with P.08 Webbing, First model ( 1915) Steel helmet ( the ribbed-dome one) and SMLE rifles, Vickers and Lewis Guns.
After WW I, the Portuguese decided to maintain the .303 calibre for Service Use, with the Navy and Airforce utlising this calibre, as well as the MG units of the Army.
Portugal adopted the (US & British Mark VIIz) ammo as the M919, initially, then standardised it as the M923, with some production beginning at AE ( Arsenal do Esercito) in 1922. The AE made .303 utilised the British .250" Primer, but with the G.Roth patent primer pocket ( central flash hole thru notched anvil).
THis design was only abandoned in 1937, when the RWS type Berdan (two flash holes, solid anvil) was adopted, but still in .250"diameter.

IN the mid to late 1920s, AE “remanufactured” large lots of American .303 ammo, by breaking up cartridges which were showing signs of deterioration, and re-using the projectiles in 1928-date AE made .303. ( Mostly W15 projectiles).
AE continued making .303 up to 1937 at least, when Portugal adopted the German sS 7,9mm cartridge for both Rifle and MGs across all services ( althought he Navy and Airforce continued use of the .303 for MGs); AE then retooled ( with RWS/DWM assistance) to convert to 7,9mm). AE did not (to my knowledge) recommence .303 production until the 1949-1950 time period, this time with a “normal” .217 Berdan Pocket and “new style” Tubular Powder( some flake still used as well).

MY large collection of US WW I contract ammo ( and British MkVIIz) came from crates of loose .303 ammo originating in Lorenco Marques ( Portuguese East Africa) via both Interarms and Century Arms. Also my Reference collection of dates and case load varieties of AE .303 (1922-1937)…Powder charges, bullet weights, primer types, crimp styles, Berdan pocket styles) numbers over 100 examples.
Included in the “Loose crate” were also TWO 100 round (empty) packets, one “M919” and one “M923” marked ( typical steel-edged card packets, sealed by tied cotton tape.)

After WW II, nearly all .303 ammo was relegated to Colonial use by Portugal in suppressing Liberation revolts ( Angola, Mozambique, Equatorial Guinea); whilst most of the Army’s Vickers guns had been long converted to 7,9mm, there still remained Airforce guns in .303, and the Navy still had its SMLEs for Shipboard use.

Going back to WW I, Britain had also bought a lot of Dupont MR rifle powder for loading in Britain ( the Mark VIIz); much of this powder was also burnt or dumped in the North Sea after WW I, as it suffered from rapid deterioration as well.

As an aside, Western Cartridge Company did introduce neck annealing of Military cases in 1915, with its Russian contract ammo…the US gov’t only adopted this feature in the mid-1920s, when it found itself with Billions of rounds of ( Wartime).30 cal M1906 with splitting necks, and the needs of Semi-Auto rifles in Rapid fire ( better chamber sealing).

Another fate of US-made ( and also British made ) WW I .303 was that after WW I, millions of rounds were repacked into surplus British-made 7,62 Russian Trapezoidal ( Wedge shaped) 15 round Packets; This ammo ended up in Australia somehow, and when an inner-city Ammo store in an Army Barracks was cleaned out in about 1970, a semi-trailer load of Oil drums full of this ammo was sent to be Burnt at a major ammo depot in the country…several 5 gallon buckets of this ammo “fell of the back of the truck” en route to destruction, and I managed to swap fresh .303 ammo for it with the user at the Rifle range ( he was merrily blasting away this WW I (collectible) ammo, not knowing (a) the collectibility) and (b) cursing all the Hangfires and Misfires and Gas blowbacks from split cases.

I still have some of the original Wedge Packets (NO labelling at all, ever?), as well as a lot of “collectible” British Cordite and Nitro (Ball) loads for all years of WW I, and all makers.

So, besides Portugal and the Balts, Britain disposed of a lot of “dud” ammo to at least Australia, if not other Empire countries, to be used up, probably in training.

Sorry for the long winded reply, but one thing led to another, after the mention of “US Contract .,303 in WW I.”

Doc AV

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Doc: There’s one biggish question I’ve had for a good while about the use of the .303 cartridge by “others” post-1918. That question is: Can anyone identify the ammunition in this caliber used by the Japanese navy before it began making its own ammo in the caliber in 1940? That service adopted the .303 no later than 1929 but seemingly acquired ammunition from abroad for a decade before deciding to produce it at home. This protracted importation of materiel that could have been made at home seems odd to me. Have you encountered any likely candidates to be from this non-Japanese source? Jack

The earliest IJN Naval 303 I have seen is with a “99” date ( 1939–Elks’ book);
But, as you mentioned, Japan did acquire and use foreign .303 ammo earlier than that.
All this stems from Japanese observations in WW I ( they were part of the Allies, and although their contribution to the war effort was limited to Convoy escort duties for Aussie convoys from Australia to both the Middle east and to Britain, IJN officers, being highly educated men (usually in Britain at Greenwich Naval college) would have noted the efficiency of the .303 Mark VII ball for Aircraft and Anti aircraft use ( at the time).
In the early 1920s, Japan ordered a quantity of Lewis and Vickers Guns for trials, along with large supplies of Kynoch Export .303 ammunition ( which was to the same specs as the Military accepted Mark VII ammo, although the export lots were differently headstamped.).

BY 1927, they had stabilised on a Vickers Aircraft belt-fed gun for Fixed mounting ( Type 87–1927) and a flexible (stripped) Lewis Gun for Observer Mounting (??T87?) As well, they used a similar, but fully shrouded Lewis for AA use on small to medium ships, as the (Naval) T92.( the most commonly seen Japanese Lewis).
After the Manchurian Incident (The “9-18” or 18 Sept.1931) supplies of anything military from Britain to Japan were embargoed, so I would say that the IJN was or had been making .303 ammo from before this date…probably unheadstamped ( even though Naval Manufacture).

The fact that nobody has shown up packets of pre-late-1930s production of Japanese 7,7 x56R, does not mean that it was not produced, just that it was probably all used up or lost at sea.

The Army, concurrently, had also acquired Vickers Air models etc for its Airforce, but ammo development only took the .303 (7,7mm) projectile, and they developed their own cartridge case, the semi-rimmed Type 89,( 7,7x58SR) for a flexible Nambu developed, Pan-fed ( Vickers pan design, from the Vickers F model and the Vickers GO(Mod.K) gun); this cartridge was then further upgraded to the 7,7mm type 92 for Ground use ( again in a modified Nambu gun of the same design as the earlier Type 3 ( 1914) in 6,5mm.).
Japanese Army Airforce Planes used the T87 Vickers Aircooled with type 89/92 ammo (semi-rimmed) using a Vickers-type Prideaux Link ( as did the Navy, but in 7,7mm Rimmed, with a clone of the British Vickers Prideaux link…what a confusion…the same gun design, two different cartridges, two different link sizes.

Doc AV
AV Ballistics.

Thank you DocAV for the info you posted. It is very interesting and informative to be sure.
As for the over-sized 5" powder charges, no I said nothing other than "did you contact Crane,ID or NAVORD as to the problem?"
I was a Chief Gunnersmate at the time and had no clout anyway to help him out.

I cited the date 1929 as the beginning of regular use of the .303 by the IJNAF because I had convinced myself that both the Japanese army and naval air forces had adopted synchronized Vickers guns in 1929. Actually Goldsmith in his Vickers book gives 1929 as the date the army took on the type 89 Vickers but he only says the naval synchronized Vickers was the type 97, adopted in 1937.

Goldsmith is silent on pre-1937 use of the Vickers in the naval air service, tho he does say the navy bought .5 guns, regular infantry tripod mount guns, and light pan-fed guns for naval launches and the like. He does include a table of purchases of synchronized guns delivered to Japan from 1920 to 1937 totaling 1674 guns, but seems to identify these as army purchases. Caliber is not given for these, and of course after 1928 the army and naval guns would have been in different calibers, 7.7 m/m semirimmed for the army, 7.7 m/m rimmed (.303) for the navy.

Reading between the lines, however, there is a suggestion the Japanese naval air force did use synchronized Vickers in their planes well before 1937, tho no known specimens seem to have survived nor is their designation known. Parenthetically, it can be said the naval air force adopted the Lewis as an aircraft flexible gun in 1932 as the type 92, in .303 of course. The most tantalizing bit, for me, in Goldsmith’s Vickers for Japan chapter is the comment one of the Mitsubishi Zeroes captured intact on Saipan in 1944 carried as synchronized cowl guns one each Japanese- and British-made Vickers. The serial, if known, would have helped correlate that latter gun with recorded serials of Vickers known to have been supplied Japan.

My thought about .303 ammunition for the Japanese navy pre-1937 (1937 is a known date of production of this caliber by the Japanese army for naval contract; the navy’s own production began in 1939 [not 1940 as I said]) is that they procured it in Britain and when specimens were uncovered during the Pacific war they were thought to be materiel taken from perhaps Singapore and not a prewar commercial contract item. Jack

The Kynoch Contract (export) ammunition, esp. .303, was marked simply “K -two digit date”, whilst the British Army and Airforce deliveries were "K two digits(army) VII (mark Seven) or “K four digits ( “Red Label” Air Service) VII”

US Ordnance in the Pacific, not being au fait with the differences between Kynock War Office and Kynock Export headstamps, “assumed” that it all came out of Singapore ( which a lot did, as the IJN was a great user of British Cordite .303 from captured stocks).

Doc AV

[quote=“DocAV”]The Kynoch Contract (export) ammunition, esp. .303, was marked simply “K -two digit date”, whilst the British Army and Airforce deliveries were "K two digits(army) VII (mark Seven) or “K four digits ( “Red Label” Air Service) VII”…

Doc AV[/quote]

Sorry Doc, but I have to take issue with you about this.

Unless the export customer wanted a specific headstamp (and I cannot think of one in .303 inch calibre) Kynoch used British style military headstamps on their export .303 inch ammunition. After the change in British military nomenclature in 1926, Kynoch continued to use the “old” style British military markings on their export .303 inch up until WW2.

Thus ammunition they sold abroad for the thousands of Vickers and Lewis guns in air force service around the world was typically headtamped “K xx VII” for ball, “K xx VIIG” for tracer, “K xx VIIB” for incendiary and “K xx VIIW” for AP, where “xx” is a two digit date. Even though much of this was Red Label quality it seems that a two digit date is most often found, although four digit dates do exist.

A good example of this practice is the Kynoch Trade Pattern Buckingham rounds taken into UK service as an emergency in 1939/40. These rounds, similar in external appearance to the B Mark IV but internally different, were given the nomenclature of “B Mark IVz*” and were headstamped “K39 VIIB”. (There were also some headstamped “K 1940 BZ” with a slightly different bullet). Quick scan attached.

I cannot recall seeing any pre WW2 .303 inch export rounds headstamped simply “K two digit date” as you describe so would be interested in seeing any examples you have. I have a number of Kynoch drawings of export rounds and none show this headstamp.

Post WW2 Kynoch changed the headstamp style and used a number of variations. The rounds sold to Argentina for use with the Lancaster and Lincoln aircraft were headstamped “K48 B4Z”, K48 G2Z", “K48 W1Z” etc and had appropriately coloured bullet tips. I also have undated “K .303G3Z” and “K 66 G2Z” as examples of other styles.