Henri-Gustave Delvigne

Henri-Gustave Delvigne (April 10, 1800 in Hamburg – October 18, 1876 in Toulon) was a French soldier and inventor. He became a captain in the French infantry service, from which he resigned on the outbreak of the 1830 July Revolution. Delvigne revolutionized rifle technology and rendered it proper as a weapon.

In 1826 Delvigne invented a new method which greatly simplified the use of rifled guns, and created a rifle known by his name. In this rifle the chamber was smaller than the bore, with which it was connected by a spherical surface equal in radius to the ball used. The powder was poured from the muzzle into the chamber, upon which the ball rested when dropped into the bore. When forced against the chamber rim by ramming (with three strokes of a heavy ram), the bullet would become deformed and flatten, so as to expand in diameter against the inside of the bore, allowing the bullet to press against the rifling grooves. When fired, the bullet would accompany the rifling and spin.

In an evolution to this first method, Delvigne introduced a wooden sabot at the bottom of the bullet, which would limit the improper deformation of the lead bullet, but still allowing for its radial expansion to fit the rifling grooves.

According to the artillery historian John Gibbon:

"Delvigne, by placing a chamber at the bottom of the bore of an ordinary rifle, and making use of it to force the ball, dropped loosely into the bore, did away with the great objection to the use of rifles in war, the difficulty of loading them, and gave an impetus in regard to investigations about the arm, which has created a perfect revolution in the system of arming infantry, by leading to the present efficient weapon. This event led to the adoption, in 1842, in the French Army, of the chambered carbine and rampart rifle-musket firing spherical ball"

In all these cases the radial deformation of the ball against the rifling grooves would permit a more efficient spinning of the ball. As a drawback, the very deformation rendered the bullet aerodynamically less efficient.

From 1830, Delvigne started to develop cylindro-conical bullets. The stability of the bullet would be further improved by the introduction of the Tamisier ball groovings. However the introduction of ball groovings hampered the expansion of the bullet against the rifling grooves.

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