303-22 short range

Have in the collection a 303-22 short range. Was looking at something else with the loop and noticed that the lead .22 long rifle type bullet in this cartridge has what looks like the top of a thin copper jacket about half way down from the nose. Bullet has 3 cannelures with the top one halfway on the copper and halfway on the lead. Is this correct or is the lower half of the bullet just copper plated? Hdst is: 12 o’clock R^L 2 o’clock 27. 6 o’clock VII.

There were three versions of the .303/.22 Machine gun training cartridge developed between 1925 and 1929, but none ever entered service. They were intended for use in indoor 25 yard ranges in Vickers guns with specially modified barrels.

The first pattern used an all lead 40 grn. bullet with 10 grns Neonite which gave 2100 fps, but also problems with leading.

The next version used a 10 grn. all aluminium bullet with again 10 grns. of Neonite to give 2600 fps. This was found to have considerable penetrative qualities and punched holes in the 1/4" steel back plates used on the indoor .22 training ranges.

The final version, which you have, had a 40 grn. lead bullet with copper gas check and first used the same charge as previous. After trying various charges it was found that the best performance that still operated the Vickers gun was 8.5 grns, giving 1900fps.

Although formally recommended for service the project seems to have quietly died. The rounds are found with R^L headstamps of 1925, 27 and 29. Of the three, the aluminium bulleted version is by far the rarest.


Thank you for introducing this cartridge, and explanation. I am impressed.
Did not know of his existence.


Tony, thanks for the complete run down. Did not think my old eyes were deceiving me. Looked more like a jacket (gascheck) than plating. Was in weapons but not a machinegunner during the Korean war. MG sections were still training with the 22 adapter for the BMG used .22 L.R. cartridges in a steel adapter so leading was not a problem. Besides I used mo-better things like Bazooka, Flame thrower and demolitions.

Another round that was briefly adopted for the Vickers gun in 1913 was the “Cartridge Machine Gun Blank .303 inch Mark I”.

It used a special constricted barrel and the chamber had a low shoulder to prevent a live cartridge from inadvertently being loaded. It was little used and disappeared with the advent of WWI. Subsequently normal Mark V blanks were used with a muzzle constriction or special barrels.

Another round of interest is the Canadian .303/.22 developed during WW2. I believe it was a University of Montreal project commissioned by the Canadian government to investigate high velocities. It utilised a different case to the .303/.22 Vickers as can be seen in the attached pictures. Headstamp is a normal Canadian “1942 DI Z”. I am sure Paul Smith can give far more detail.


These rounds are attributed to C.D. Merridth who was working at the University of Toronto during the war. There were a huge number of variations on a number of cases. These rounds are the most common.

The round on the right has a small lead point.

This photo is of a .280 necked down to a .22. It is believed to have been developed by S.G. Newton who was working at Dominion Arsenal during the war. Headstamp is KYNOCH .280 NITRO

Tony and Paul. Thanks for all the great info. Didn’t think my one little cartridge has so much history behind it. Looks like machine gun adapters could be a study in itself!

gam gjm

gamgjm, I believe your round is legit, but the basic concept, a necked-down .303 with a .22 bullet, is a relatively common wildcat. I’ve seen a number sold as rare military experimentals.

These 4 rounds are all different versions of the 303-22
Another terrible picture, but the 303-22 other than the military rounds developed for short range machine gun practice are very common and were a wildcat derived from the 303 cartridge .
The basic reasons for these rounds, was the affordability of the converted surplus military rifles and brass to create a high velocity hunting round that would perform well on soft skinned animals.
[Much like the 25-06]
Anyway to cut a long story short, they come in many sizes, case lengths, shoulder angles, projectile types etc. as many backyard gunsmiths developed their own reamers and re-barreled S.M.L.E. rifles.
They were also commercially available in re-formed and new brass from companies like Riverbrand, Super Cartridge Co., Sportco . etc.

Jon C and Terry are right. There are many wildcat 22s based on the 303 case and a few have been touted as experimentals. So be careful.

And for every 22/303 there is a similar or identical 22/30-40 Krag wildcat. And a few to spare.