.22 centrefire



Anyone have examples of a .22 centerfire that was marketed by RWS in the mid to late 1930s?

The round was based on the same principle as the 4mm M20 round, where a primer was fixed into the inside of the cartridge case. They have the same dimensions as a .22lr round, but a clear visible crimp around the base, this helps to keep the primer in place.



Is this what you were looking for?



Paul, that’s the one! Thanks.

This is RWS’s ‘Marke “N”’ brand.


I wonder if RWS/GeCo were the only ones to make them, or that other manufacturers made them as well?


What was the advantage of these? Surely they would be more expensive to produce (therefore more expensive to buy), and you would also have to buy a new rifle.


The only advantage I could see is fewer misfires. While fantastically good these days when the production levels of .22 RF ammunition are looked at (the billions of rounds made), the fact remains even
in very good RF ammu, the rate of misfire is much higher than that of equal quality center-fire primers.

When I was shooting NRA-Style Bullseye Pistol, I used T-22 for most practice shooting, and while this represented only a very small percentage, after 15 or 20 years of shooting, I had almost a full box of mis-fires sitting on mmy shelf. My plan was to fill the box and then send it to someone I knew at Winchester as a joke. As I got older, I decided it would not be much of a joke telling him it was all from one box, but really, a rather stupid prank, and I ended up scrapping them.


never having built a rifle, would the centerfire advantage be that you would not have to build a new bolt but use a smaller centerfire bolt and receiver? And not have to retool the whole action?
VLIM I do have a centerfire 22 with no headstamp so there may be another supplier. Vic


Your idea is a good one Vic, I didn’t think of that. Sub calibre training with inserts seems a very good idea of their intended use.

I was once shooting regular RF .22s and had misfires (PMC ammo) and had a few misfires. I simply rechambered them at a different angle and fired again and they worked as normal. I thought that if the rifle had a bolt with two firing pins like the old Swiss Vetterlis then the misfire rate would be alot lower.


Vic is correct.

This little quest started after a fellow collector showed me a typical RWS subcalibre insert for the P08, but not in the common 4mm M20 shape. He thought it was a .22lr insert, because it would chamber a .22lr round. Attempts to fire .22lr rounds with it failed, however.

Since these inserts rely on the original centered firing pin to touch them off, the conclusion was that there had to be some sort of .22lr shaped centerfire round for it. A quick browse through the 1936 RWS catalog showed that indeed there was such a thing, and it specifically mentions use in a subcalibre insert. The basic principle is exactly the same as the 4mm M20, also covered by the same patent.

I don’t think it was a large sales success and one would certainly expect ‘issues’ with both cartridges used in centerfire and rimfire guns.


In a Parker Hale catalogue from c1930 it shows the aiming tube which was a .22" barrel which was inserted in a .303" SMLE. The RWS CF .22" ctg was shown with this and the advantage was that the user did not need a RF bolt to use the tube.