Lesmok Powder Question


Hello Everyone,

I was wondering - Around the year 1913, was Lesmok Powder being loaded ONLY in North American made cartridges? (Specifically .22LR)



As a continuation from the post above:

I note that Dominion Cartridge Company, CIL, US Cartridge Company, REM-UMC, Clinton Cartridge Company, Winchester and Western Cartridge Company use Lesmok powder. All of which, are in North America.



Is your search for users of and usage date range for Lesmoke related to the unknown .22 RF box recently posted here on the Forum?:




Yes it is! This is why I asked… I will be writing up a small article for the Journal regarding the unknown .22 box.

I did check out the first link you posted, and this is what got my gears turning on the Lesmok aspect of the unknown .22 box.




Excellent idea to put it in the Journal.



Brian, with your expertise and knowledge, would you say that Lesmok powder was used strictly in North America around the 1913 timeframe?



Lesmok was in production far beyond 1913. I can recall that when my father was a smallbore target shooter in the late 1940s a competitor or two at matches still used cartridges loaded with Lesmok. This ammo wasn’t likely of 1947 manufacture, but it was still fresh enough for a competitor to use. My father said you could readily pick up the black powder aroma.



PM sent.



Thanks for the input guys!

I just sent DuPont an email, and I hope to hear back from them with some useful information.

(There is a wait time of 3 buisness days for a reply).



I did a little more looking around on the lesmok question, and the short version response is that WRA and Remington made .22 match ammunition using lesmok until the late 30s or even just before WW.2. Peters loaded .22 with their own proprietary King’s semi-smokeless until the 30s, but when Dupont acquired Peters in 1934 Peters began loading Dupont’s lesmok instead. The smelly lesmok-loaded cartridges my father told me about were most likely Winchester Ezxs. Jack


I mentioned the lesmok thread to a friend, who came up with something I’d missed: Julian Hatcher, in his Hatcher’s Notebook, stated that in 1947 Winchester loaded its last lot of ammunition with lesmok as a propellant. Jack


Jack, most interesting! I did not know Lesmok was loaded until 1947 by Winchester.

Thank you for this info!

With regards to my original question, if Lesmok powder was used specifically in North American cartridges…

With all the research I’ve done thus far on the original subject, I can’t find any non-North American company’s who loaded Lesmok powder around 1913.

My fascination with the 1913 year is because of the .22LR box that EOD posted some days ago.

^^^ Brian mentions the link above.^^^



Both types were physical mixtures of fine-grained black powder and a fast burning nitrocellulose that was very close to “guncotton”. King’s Semi-Smokeless (KSS) was first loaded by Peters in 1897. Peters held a series of patents covering formulation, manufacturing techniques and machinery needed to make KSS. KSS became a rapid success (mostly for .22 rimfire, both Short & LR) because it produced quite accurate ammunition and the rifle did not need to be cleaned every few shots. DuPont chemists tried for 10+ years to come up with a similar powder that could be made while skirting the Peters patents. Lesmok was the DuPont product. Info source is “Nitrocellulose Industry” Vol 2, by Edward Chauncey Worden, D. Van Nostrand Co., NY, 1911.

That the manufacturing processes (at least two) were fraught with patent & legal issues may well have discouraged other makers.

Whelen (The American Rifle, 1918) wrote that ammunition loaded with either powder had a short shelf life where accuracy was of primary interest. “If you bought a case in April, accuracy would drop off by August.” Sharpe (Complete Guide to Handloading, 1937) said that both types had been sold to handloaders, but that he considered the stuff too dangerous to use.

Both types of Semi-Smokeless were commercial successes for so long because the early smokeless powders and priming compounds developed for them were very corrosive. Once stable and otherwise reliable non-corrosive priming compounds were developed, semi-smokeless was abandoned.


Lesmok was a mechanical mixture of black powder and guncotton; King’s was black powder and smokeless powder. It is, I suspect, likely that King’s was somewhat less sensitive to pressure and friction hence available in canister lots, whereas lesmok never (I believe) was. While Sharpe came down hard against both these propellants Naramore (1937) spoke positively for King’s as a handloading propellant. Jack


Jack prompted me to dig out my battered copy of Principles and Practices of Loading Ammunition, Earl Naramore, 1954. He wrote a long paragraph about each.

About KSS, he wrote that it could be loaded in any of the old black powder cartridges (presumably straight ones). It was made up to about the beginning of WW2. “virtues are not sufficiently great for anyone to put themselves out to obtain it.”

About Lesmok he wrote “if the reader should by chance come into possession of any, get rid of it quick.” “It is the most dangerous powder to load that there is. Can be fired by friction or by a blow. Flare-ups occurred in the ammunition plants.”


Back when I was a youngster in the 1950s, KSS was fairly popular among the local muzzle-loader shooters (there were a lot of them where I came from, as it was the home of the NMLRA), I had several empty KSS powder cans at one time. There was one local dealer (E. M. “Red” Farris) who had a large inventory of it and sold it to the ML shooters.