The Davoust Shot Concentrator: A French Answer to Unruly Patterns (1855–1859)
Nineteenth‑century hunters wrestled with two maddening behaviors from smoothbore shotguns: at one extreme, tightly packed pellets that flew out “like a ball” (the coup de balle), and at the other, errant flyers that blew patterns wide open. Period writers traced both to how the wad pressed or failed to press the shot during ignition: over‑compression could keep the column clumped for several yards after the muzzle, while under‑compression let pellets collide, deform, and veer off‑axis.
Pierre‑François Davoust, an armurier from Alençon, set out to cure both problems at once.
What Davoust built
Davoust’s cartouche à projectiles divisés was a self‑contained shot cartridge that left the barrel intact and then opened in flight. Contemporary descriptions outline a three‑part cylinder:
(1) a thin compartment with a “white dust” spacer to isolate the powder;
(2) a spongy wad ending in a small conducteur that deploys immediately outside the muzzle; and
(3) a paper shot cup capped and held by elastic binding.
The conductor keeps the cartridge on line for the first ~10–12 meters, after which the cup sheds and the shot spreads evenly without pellet‑to‑pellet battering.
Davoust’s patent literature renders the same idea mechanically: a fabric disc and string form a parachute‑like conducteur; the shot cup opens beyond the muzzle roughly at 12 meters. The cartridge was designed both for ramrod loading and, with a simple adaptation, for the new breechloading douilles.
How it was used
Loading was intentionally simple: pour the powder, then slide the whole Davoust cartridge above it, no separate wads for powder or shot. Writers in Journal des Chasseurs even remarked that, for a conventional muzzle‑loader, it was as fast as dropping a cartridge into a Lefaucheux breechloader and often quicker than dealing with a Beringer after‑shot extraction.
Davoust marketed two versions. The petite portée began to open at roughly 4–5 meters from the muzzle which wasgood for early season and woods shoots as well as the long‑range variant which held together “like a ball” out to about 15–16 meters before releasing, a better fit for late‑season fields, marsh, and driven days.
What period testers claimed
Period trials credited the Davoust cartridge with roughly double the penetration of an ordinary charge of equal powder, an effect attributed to better gas sealing and more efficient use of the propellant.
They also reported an eye-catching safety observation: with Davoust cartridges seated above, but not touching, the powder, experimenters fired hundreds of rounds and even plugged the muzzle with earth without bursting the barrel. Repeating the ‘plugged muzzle’ test with a normal load split the tube. The magazine printed this without a firm physical explanation, but presented it as a consistent experimental result.
Two drawbacks were noted: cost (adding 5–6 centimes per shot) and early heat-related failures of the rubber cap that could dump the shot, an issue Davoust addressed with stronger closures and, if needed, a gauge-sized wad that would still retain pellets even if the elastic failed.
Evolution under patent
Davoust filed a 15‑year patent on 25 April 1855, then iterated steadily. Certificates of addition in 1856–1857 refined the mouth geometry of the shot cup (flared for quicker release, constricted for longer hold), described the parachute conductor and its string, and detailed a version whose cup splits lengthwise so it opens as soon as it clears the muzzle which was useful for the petite portée behavior.
A later 1859 certificate even replaced the rubber binding with heavy thread: three external ties braced the long‑range model from cap to sabot, then passed through the wad, yet another attempt to make the closure more heat‑proof in heavy use.
Why it mattered
The Davoust cartridge was part of a broader mid-century push to tame shot patterns for specific game and distances. By delaying pellet release in a controlled, repeatable way, and by making the whole process quick to load for both muzzle-loading and breech-loading guns, Davoust gave hunters a practical ‘concentrator’ years before plastic shot cups and modern wads standardized the idea. Period writers, including Baron du Casse, went so far as to dub it ‘universal’ after London demonstrations, an enthusiastic label that captures how novel the concept felt in the late 1850s.
Références
Journal des Chasseurs. “La Cartouche Davoust.” Vol. 22, 2nd Semester, 1858, pp. 244–247.
Description des machines et procédés spécifiés dans les brevets d’invention, sous le régime de la loi du 5 juillet 1844. Tome XLIX. Paris: Imprimerie Impériale, 1855–1859. Patent no. 13653 (Davoust, 25 April 1855) and certificates of addition, 1856–1859.
La Chasse Illustrée. “La Cartouche Davoust.” Première année, no. 22, 28 décembre 1867, p. 176.
À PROPOS DE MOI
Bonjour, je m'appelle Aaron Newcomer. Je suis collectionneur et chercheur sur les systèmes d'armes à feu à chargement par la culasse du début du 19e siècle, avec un intérêt particulier pour les travaux de Jean Samuel Pauly et Casimir Lefaucheux. Je collectionne les cartouches et les documents liés à ces types d'armes à feu et je mène des recherches sur ces sujets, approfondissant ma compréhension et ma connaissance de ces armes historiques et leur place dans l'évolution de la technologie des armes à feu. Ma collection et mes recherches reflètent mon engagement à préserver et à comprendre l'histoire et les innovations techniques de ces systèmes d'armes à feu anciens.
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Very well done, interesting, great illustrations. Thanks!