Carabine à tige

Delvigne had developed chambered carbines and rampart rifle-muskets so that 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.

After only three or four shots, a typical rifle would be impossible to reload without using a mallet to force the bullet down the fouled barrel.

Delvigne's design addressed this problem by introducing a projectile that was smaller than the bore of the barrel (so more easily bypassing the accumulation of fouling) which after loading could then be struck with a ramrod.

When hit by the ram, the bullet expanded radially against the rifling grooves and at the same time wrapped around the stem, giving it a more efficient and aerodynamic shape.

[4] This system, although an improvement over Delvigne's method, still did not allow for a perfect engagement in the rifle, rendering the ball's trajectory rather erratic.