Delvin system

By the beginning of the 19th century, rifled rifles were well known, but their use was hampered by the fact that with the generally accepted method of loading from the muzzle, the bullet had to be driven with a ramrod over the rifles, which took quite a long time. As a result, such guns could not compete with smoothbore in terms of rate of fire, and were used only to a limited extent, by the best shooters. Delvin was able to eliminate the described drawback by developing a rifle with a free bullet. In the breech of the Delvin rifle there was a chamber in which a powder charge was interrupted (for this reason the rifle was called chamber). Since the chamber had a diameter slightly smaller than the diameter of the barrel, a ring-shaped protrusion was placed on its upper edge, on which the bullet lay during loading. The round bullet had a diameter that allowed it to freely pass the barrel during re-entry. With two or three strokes of the ramrod, a soft lead bullet was broken on a ledge, expanding to a degree sufficient to crash into rifling during firing. The ramrod head had a hemispherical recess, allowing the pool to maintain the corresponding shape of the head. The rifle was adopted by the French army, from 1830 a cylinder-conical bullet was used for it. The system had certain disadvantages: if the protrusion of the chamber was too narrow, or the diameter of the bullet was too small, then it was driven into the chamber and did not crash into the rifling. Also during the shooting process, when powder deposits accumulated in the chamber, the standard charge of the powder did not fit completely into the chamber, protruded above its edge, preventing the bullet from lying on the ledge and achieving its expansion ^[1] . Officer Thierry proposed using a wooden pallet for bullets that would prevent bullets from entering the chamber and wrapping them with a salted patch to reduce the contamination of the rifling. The Delvin rifle with a Thierry bullet (Thierry choke ) was adopted by the armed forces in 1840, but the latter was not widely used, since already in 1842 a more advanced Tuvenen system rifle was in service ^[2] .

Markevich V. E. Handgun / Volkovsky N. L. .. - SPb. : Polygon, 2005 .-- 496 p. - ISBN 5891732769 .