Tamisier

François Tamisier (1809, Lons-le-Saunier, Jura – 1880) was a 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).

Ball grooves

Captain Tamisier obtained a patent 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 (fletching), or shuttlecocks. 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.