Type of powder in WRA 1941 .303?


What type of powder was used in the .303 ammunition made by WRA that had the headstamp “W.R.A. 1941 .303”? I am interested as I am sectioning some .303 rounds, including this one. I would like to know what the powder looks like so I can make some imitation powder. I believe it was one of the types with rod-shaped grains when I saw some of these rounds dismantled a while ago.

Thanks for any info.


I pulled some WWII-era WRA .303 rounds apart years ago, and it had a stick-type perforated powder, not Cordite, flake, or ball. I have no idea what specific type (single or double base, etc.) it was, but it looked something like the IMR series. I’d guess anything that looks like IMR4895 would be close.


Some of the wartime WRA .303 did use ball powder, but I’d wonder if the 1941 production didn’t typically use the perforated stick. Jack


Thanks for that. I have made the replica powder out of the insulation from thin black electrical wire. It looks very close to what I remember the real thing looking like.


i have a round of 303 wra and the powder in my round is ball powder type


Falcon–I don’t understand why you feel the need to make fake powder for your sectioned cartridges. Why not just use some of real powder mixed with a little Elmer’s White Glue. The glue drys completely clear and can’t be seen. I have never tested it, but with the coating of glue, I doubt if the powder is even very flammable, if that is your concern.


I don’t have the powder as I have to have everything inerted before I can even own it. If I make imitation powder it also ensures that it is 100% inert. I was also concerned about how flammable it would be, having seen first-hand how well powder does burn when exposed to a flame.


I did some internet searching on the WRA .303 Mk 7Z and didn’t find much, other than the round used a nitrocellulose propellant. Unfortunately, I don’t have any of the old .303s left to disassemble. What I had done some years ago was to pull the WRA FMJ bullets and replace them with soft points, using the same powder. I don’t know what the headstamp year was, other than WRA and from WWII. I also remember that they were packed 20 rounds in a two-piece box.

I did find one interesting fact about the WRA Mk 7Z - its use was restricted to only the SMLE, as apparently the round did not function properly in the Bren gun. I find that strange. Does anyone know more about this?

While we’re on the topic, I have an empty British Mk 7Z wooden crate which is marked as being for aircraft use, and oddly it has an expiration date stamped on it. Does this expiration date have something to do with gun timing? If anyone wants to see a picture, I can provide it.


“Use by” dating of .303 for Aircraft ammo was common up to the end of WW II, and even later (Canadian Mk7z in the 1950s)

Aircraft ammo had top have reliable Primers, hence the extra high quality primers used in “Air Quality” ( more commonly known as “Red Label” ( the typical British Military label was printed in Red, rather than Green or Black).

It was known that primers deteriorate in time, so usually a
"one year" Use by date was printed on the outher crate or can.

The other rule was that any ammo used in a plane flying above a certain height, and returning to ground, that ammo was relegated to “Ground use only” as the Cold and Low atmospheric pressures affected the reliability of the priming compound.

Reliability of priming compound was especially important in planes with “synchronised” guns ( to fire throught the arc of the propellor)…in fact the Limitation on this ammo was [color=#FF0000]“not to be fired in synchronised Guns after dd.mm.yr.”[/color]

Finally, in British ( and Empire) service, ammunition for “Air Service” was headstamped with the Entire Year ( four digit) date; Land Service only was with a two digit date. By 1943-44, the Quality of priming compund had increased so much, that All .303 ammo ( Land and Air) was simply dated with a two digit date, BUT some Lots of 1945 ammo ( R^L) for Greece had the four digit date ( and Cans were “Red Use-by date” stamped accordingly)

In the Case of US contract ammo, whilst Remington had the stamp " .300Z" on its .30/06 ANM2 ammo for Britain, the WRA .303 did not have any “Z” in the headstamp…simply a year dated ( Four Digit) WRA stamp. The WRA ( as shown recently) packets were Red Print on white carton for Aircraft Quality, and Black print for Land Use.

As to the “not functioning in Brens” that sounds like a furphy ( unreliable info)… .303 Ammo for all services was loaded to the same QA limits…only that for Air Service, the quality of the primers ( sensitivity, reliability of ignition under severe conditions) was the only “difference”…Air Quality ammo used both Cordite and Tubular grain Powder in British Loading, and Tubular Powder and Olin’s “Ball Powder” in US Contract loading.
Any “Air Service” Ammo used by ground forces was either “life expired” in its synchronised gun role, or, in the case of RAF ground units ( Airfield defence etc) Down-graded Air-type ammo after having been up in the Cold sky.

Doc AV
AV Ballistics.
Doc AV


Whilst most of what DocAV states is spot on, the last paragraph is not strictly correct.

The quality of the Winchester ammo was not particularly good and much of it was relegated to a lower use than it was intended for. Army Ordnance Services Pamphlet 11 (February 1945 edition) states:

[i]No Winchester .303 in. ammunition is considered suitable for use in aircraft although Red Label ammunition from Lot 45 of 1941 onwards may be used in an emergency. Packages containing this ammunition should bear the restrictive marking “NOT FOR USE IN AIRCRAFT”, though it is known that some has come forward without this marking. The ammunition is fit for normal ground use unless it bears an additional restrictive marking.

Lots of Winchester .303 in. manufactured before Lot 45 of 1941 should be stencilled “FOR PRACTICE IN RIFLES ONLY”.[/i]

The subsequent edition of this manual in April 1949 went further and stated:

Ammunition manufactured before Lot 45 of 1941, previously sentenced for practice use in rifles only, will be sentenced unserviceable, without further inspection.

Thus the restriction on use in Bren guns was actually a formal ordnance instruction. Attched are some Winchester labels showing various restrictions.



Just to complete the story, following are pictures of my WWII .303 crate. As the information on the crate may be difficult to make out, the date on the crate is RL22-10-42 (stenciled). The date sticker is printed in red and says: “ALL SERVICES not to be used for synchronized guns after 22-10-44” This is two years after the date stenciled on the crate. The same information is on the opposite side of the crate, except there is what looks like some sort of safety sticker which is circular, red, and with a white 6 in the center. I would guess this is something like a HAZMAT classification designation for small arms ammunition used by the British at that time. The steel cable loop handle appears original. I’d guess that RL means Royal Laboratories.

TonyE, I note you included a box label indicating that WRA was not to be used in Bren guns. I guess what I read had some foundation in fact. Do you know what the WRA defect was to cause these restrictions?


Were the R/|\L 1945 7 rounds all made for Greece?


Dennis - I believe the problem was that the case heads on the Winchester ammo were not as strong as the British counterpart and as the rear of the case in a Bren is not fully supported (as in many MGs) ruptures and separated cases resulted. Exactly the same problem occurred when the Bren was converted to 7.62x51 as the L4A1 etc. The early British L2A1 ball cases were not strong enough and separations occurred. The case was strengthened in the web to produce the L2A2 case and although improved the cases had to be thickened again slightly before the problem was overcome.

Presumably this is also why the ammunition was sentenced as unfit for aircraft, but as the cases is slightly better supported in a Browning the ammunition could be used in an emergency.

Falcon - I am sure the RL ammo was not made specially for Greece, but was normal British run of work; however I would be interested to see any evidence DocAV has that it was specially made. Also, I have never seen “R^L 1945 7” headstamped .303. “R^L 45 7” certainly, but not four digit dated. Again, if DocAV has some I would love to see a picture of the headstamp.



I have an inert one in my collection. I will sort you out a scan of the headstamp.


I thought the problem with this ammo was premature powder degradation but I stand to be corrected in this. It seems strange to me to give a two/three year service life on ammo that had a weak case head since the problem would be present from day one and wouldn’t be exacerbated by the passing of time.

This ammunition used to turn up for shooting well into the seventies, I had some even into the eighties but performance was poor. Occasional soft rounds and erratic.


Perhaps you are confusing the specific cause with the specific restriction. The weak case head–yes, undoubtedly in evidence from the day the cartridge case was drawn–affects use in a BREN, or other MGs where the case head is not fully supported; but does not synchronization. The powder degradation in this ammo and also identified in other lots, manufacturers, etc. results in the loss of standardized “hang time” that would prevent use in synchronized (firing through propeller blade) use after two years. The two are only slightly related in that the .303 would still be useful in bolt rifles, and the synchronation never impacted the BREN in any use. Hope this helps.


I bought the last 200 rounds our local dealer had in WRA 1942 and 43 .303 two years ago. I have fired about 25 of them but between “washing” the barrel after very shoot and getting very poor results (all over the ISSF 300 meter target) from a Enfield No4, Not worth it. Pulled the bullets.


The cases would also be good for reloading as they are boxer primed.


For those interested in them, I say these on GB. Cheers, Bruce.

gunbroker.com/Auction/ViewIt … =220711084


Anyone thinking of shooting this ammo should be aware that it “agressively corrosive”. You can almost hear the corrosion happening!

Falcon, there is nothing special about the cases for reloading, there are plenty of better quality boxer primer .303 cases readily available in the UK such as HXP, S&B, PPU etc.