ID needed for 2 (Austrailian Wildcats?)

I was just digging through a can of cartridges and came up with two of each of the following:
Number one - Case is headstamped RIVERBRAND 303 BRITISH
The new cartridge is a necked rimless

Number two - Case is headstamped MF 54 7 (is this also a 303 Br. case?)
The new cartridge is also a necked rimless
Bullet------.218 (seated deep, must be .224)
Neck ------.255
Do these guys have a name? Thanks:Jack


Give us the base to shoulder dimension (body length) and shoulder angle.

These are two of the most important dimensions in IDing a wildcat.

Full-frontal photos are even better because you can print them out and scale all dimensions.


The base to shoulder on number one is - 1.775
The base to shoulder on number two is - 1.567

There were a number of .303-based “semi-wildcats” that were developed in Australia. The one on the left is probably a .303/.250 Rimless, and the right is a .303/.22. At least, those were the names I used in my old catalog, based on what an Australian told me they were.


I think Cyberwombat has it.

For wildcats, the 303 case is to Australia as the 30-06 is to the the USA. Most wildcats were meant to be used in the SMLE or Enfield and so they were rimmed. The user of your two must have had another rifle in mind when he removed the rim.

The 25 caliber wildcat (in the rimmed form) is called the 303/25 or 25/303, take your choice. Later, Super made brass which was headstamped SUPER 303-25. I think Bertram still makes 303-25 brass.

The 22 caliber is nearly identical to an Australian wildcat called the 22/303 Sprinter. The Sprinter was rimmed and was designed for use in the SMLE.

The designer of your two cartridges most likely had his own moniker. Or he may have simply called them, as Cyberwombat said, 303/25 Rimless and 303/22 Rimless.

Ballistically, the 25 caliber is very close to the 257 Roberts and the 22 caliber is close to the 22-250.


The so-called “Wildcats” were factory rounds, made by Three different makers (Riverbrand, of S.A, and Super, of Victoria, and ICIANZ of Victoria)…so, a factory cartridge, even if in a small way compared to a US “Factory” cartridge.

The .303/25 and the .303/22 came in several length variations, the most common being 56mm (original .303 case length) but the .22 variants also had 50mm cases, and 45mm cases (or 43mm)
The .303/25 Rimless was also a “factory” cartridge, with the Packets overstamped “Rimless” after the .303/25.

Names are as follows:
.303/22 Full length “Falcon” .303/22 (50mm) “Sprinter”, 303/22 (45mm)
"Wasp "or “Hornet.”

Initially, in the 1930s, cases were made by simply necking down and annealing ex Military cordite cases…the annealing was required due to the particular means of making Cordite .303, which left the neck and shoulders brittle. Primers for the .250 pocket were supplied by Kynoch and after WW II, RWS (Non corrosive)…Super used RWS primers almost exclusively, and mentioned the fact on the packets.

With the introduction of Boxer primed cases, new brass could be made, with improvement in reloading capacity (Berdan Military cases usually failed after a couple of reloads)

The Rimless versions are connected with a strange conjunction of War souvenirs, Stupid laws, and ammo availability…After WW I, 7mm ammo was not readily available for the hundreds of Boer War Rifles souivenired in 1902…so Gunsmiths went about “convberting” them either to .303/25, or even .303 284 (“7mm”), This also involved converting the Bolt face and the extractor and the magazine lips…an onerous Job ( I have seen one such…a perfectly good collectible ruined with the best intentions) into a .303/25 Rimmed.
By using a “rimless” case, the only thing to change was the barrel…the Mauser Bolt handled the slightly smaller .303 (rimless) head easily.
Similarly, some WW I and WW II German Mauser 98s were converted early on. By the 1960s, the freer availability of American calibres led to the demise of these “special” conversions for Mauser rifles.

The other problems relate to NSW having a ban on “Military Calibres”…so all “Military rifles” had to be in a “Non Military Calibre” hence the .303/25, .303/270 etc. ( 1930s to 1975). Other states werren’t so anal…until 1996, but that’s another story.

Both companies (RBA and Super) produced “Remanufactured” ammo using Aussie Military once-fired (Berdan) cases, even into the 7,62 Nato era ( .303 ands all its “variants” and also .308 and .243 were made from Milsurp cases)
They even had Footscray run a few batches (initially) of New berdan cases for them, before switching over to Boxer cases in their own plants ( or made under contract by CAC (New Zealand) or ICI ( Australia).

Doc AV
AV Ballistics.
Brisbane, Australia.