François Tamisier (; 22 January 1809,

Lons-le-Saunier Lons-le-Saunier () is a commune and capital of the Jura Department, eastern France. Geography The town is in the heart of the Revermont region, at the foot of the first plateau of the Jura massif. The Jura escarpment extends to the east a ...

, Jura – 20 May 1880, Paris) 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 The Minié ball, or Minie ball, is a type of hollow-based bullet designed by Claude-Étienne Minié for muzzle-loaded, rifled muskets. Invented in 1846 shortly followed by the Minié rifle, the Minié ball came to prominence during the Crime ...

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: ''"

cannelure A cannelure is a groove or channel around ammunition, either bullets or cartridge cases. The cannelure may be pressed into or cast with the bullet or case. Function In the Minié ball the purpose of the cannelure is to hold a lubricant. Cannel ...

s"'') on the cylindrical part of the shot.''Military Dictionary'' by H. L. Scott p.510 1863
/ref> Eratic bullet trajectory

Compared to round shots, which offered a rather inefficient but symmetric 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 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. Delvig ...

.''Rifles'' by David Westwood, p.275-276
/ref> Through Tamisier's method, the resistance of the air behind the center of gravity of the shot was increased, thereby increasing its stability. 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 Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word responsib ...

was developed by Thouvenin. These principles were later incorporated in the design of the

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.''The United Service Magazine'' 1853 p.501
/ref>

Notes

{{DEFAULTSORT:Tamisier, Francois 1809 births 1880 deaths People from Lons-le-Saunier Artillery of France