British WWII Subsonic 9MM Ammunition?

Does anyone here know if the British, or any commonwealth country produced subsonic 9mm ammunition during WWII? I assume the answer is probably yes. The subject came up in a discussion in regards to the Sten SMG on one of our discussion boards, and I want to see if anyone here has an example.


David Albert

Throughout WW2 the British used standard ball ammunition in their Mark IIS silenced Sten guns.

It was not until 1946/47 that trials started with silenced Patchett machine carbines using heavy ball sub sonic ammunition.

Over the next twenty five years a great number of bullet designs were tried, mainly 150 and 170 grains in both flat based and boat tailed configurations. Generally these were identified by a coloured spot of paint on the case head. None were ever formally approved for service, but some were undoubtebly issued.

Details and photographs are on my web site: … heavy-ball


Thanks for the info, TonyE.

I looked at my Laidler Sten book, and he did not cover ammunition. Iannamico covered ammunition in his Sten book from a current U.S. NFA shooter perspective. David B. Gordon, in his book, “Weapons of the WWII Tommy” showed several examples of regular ball ammunition, as you mentioned.

I suppose I could add context to this question. The person who posed the question limited his query to WWII, because he asked about a Sten magazine marked with an “S” on its body, found in a French Resistance weapons cache about 15 years ago. His hypothesis is that it could indicate ammunition for a suppressed model. A UK member chimed in since I initially posted, and he thought it was unlikely the marking indicated such. He stated, “However, I can’t vouch for the SOE Silenced STEN with the CISA silencer so its possible that other, non standard contract 9mm ammo may have been purchased for these (But I doubt it).”

Anyway, it looks like the magazine body mark representing a suppressed ammunition loading is conjecture at this point.

Here’s the link to the thread, if you have any interest… … opic=16012


David Albert

Why would subsonic ammo require a special magazine?

All of the 9x19 subsonic ammo I am aware of is the same overall size as supersonic ball and uses the same magazines.

“S” on magazine…made by Singer Sewing Machine Co.

The only close to “subsonic” 9mm ammo used in WW II was the underpowered “9mm Luger” supplied by Winchester on lend-lease…it was suitable for Parabellum Pistols (P-08) but way too slow and weak of the Sten Gun or its relatives (Lanchester, etc)…Only when the British started to make 9mm Mark IIz with a loading similar to the German cartridge did the functionality of the Sten improve ( and “Lugers” started to fall apart)

Why Mark IIz? because the first attempt (Mark Iz) was basically a copy of the US cartridge, with all its problems.

Doc AV

Doc, Just a further point. The WRA ammo bought by the UK was all labled 9mm Parabellum because it was not the commercial WRA 9mm Luger design. It was a copy of the Finnish 9mm Parabellum with the 115gr bullet. In fact, the first lot bought by the UK was actually produced for Finland, but not delivered. This info is from Winchester records.