François Tamisier was French artillery captain of the 19th century. He invented various methods to improve the rifled gun, particularly ball grooves (not to be confused with the Minié ball

Minié ball

The Minié ball is a type of muzzle-loading spin-stabilising rifle bullet named after its co-developer, Claude-Étienne Minié, inventor of the Minié rifle...

).

Ball grooves

Captain Tamisier obtained a patent

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

 in 1841 for a method to improve the accuracy of cylindro-conical shot, by cutting three sharp grooves (French: "cannelures") on the cylindrical part of the shot.

Compared to round shots, which offered a rather inefficient but symmetrical and stable aerodynamic round profile, the aerodynamic stability of the cylindro-conical shot had been an issue in early rifled weapons of the type developed by Delvigne. Through Tamisier's method, the resistance of the air behind the center of gravity of the shot was increased, thereby increasing its stability, in a manner similar to that of arrow feathers in an arrow

Arrow

An arrow is a shafted projectile that is shot with a bow. It predates recorded history and is common to most cultures.An arrow usually consists of a shaft with an arrowhead attached to the front end, with fletchings and a nock at the other.- History:...

 (fletching

Fletching

Fletching is the aerodynamic stabilization of arrows or darts with materials such as feathers, each piece of which is referred to as a fletch. The word is related to the French word flèche, meaning "arrow," via Old French; the ultimate root is Frankish fliukka...

), or shuttlecock

Shuttlecock

A shuttlecock, sometimes called a bird or birdie, is a high-drag projectile used in the sport of badminton. It has an open conical shape: the cone is formed from sixteen or so overlapping feathers, usually goose or duck and from the left wing only, embedded into a rounded cork base...

s. The shot would thus remain stable in flight and increase greatly in efficiency. Tamisier had experimented with the ball developed by Delvigne to discover the effect of aerodynamic resistance on the trajectory of a bullet.

The Tamisier grooves greatly improved the efficiency of the cylindro-conical bullet. However they rendered the forcing of the bullet against the grooves of the rifle bore in the Delvigne system rather difficult. To accommodate this difficulty, the stem rifle was developed by Thouvenin. These principles were later incorporated in the design of the Minié ball

Minié ball

The Minié ball is a type of muzzle-loading spin-stabilising rifle bullet named after its co-developer, Claude-Étienne Minié, inventor of the Minié rifle...

.

Progressive rifle grooves

Tamisier also developed a method for making rifle grooves, which was original in that the grooves were deeper at the breech and progressively shallower towards the muzzle. This provided for a progressive forcing of the ball as it moved through the barrel, greatly improving its efficiency.