Lived Circa 1520
His shop was successful for generations, but his techniques were not widely adopted until Frederick the Great
Barrel rifling was invented in Augsburg, Germany at the end of the fifteenth century. In 1520 August Kotter, an armourer of Nuremberg, Germany improved upon this work. Though true rifling dates from the mid-16th century, it did not become commonplace until the nineteenth century.
The concept of stabilizing the flight of a projectile by spinning it was known in the days of bows and arrows, but early firearms using black powder had difficulty with rifling because of the fouling left behind by the combustion of the powder. The most successful weapons using rifling with black powder were breech loaders such as the Queen Anne pistol.
 Breach Loading
Breech-loading swivel guns were invented in the 14th century in Burgundy. They were a particular type of swivel gun, and consisted in a small breech-loading cannon equipped with a swivel for easy rotation, and which could be loaded by inserting a mug-shaped chamber already filled with powder and projectiles. The breech-loading swivel gun had a high rate of fire, and was especially effective in anti-personnel roles. The main challenge for developers of breech-loading weapons was sealing the breech. This was eventually solved for smaller weapons by the development of the self-contained metallic cartridge. For weapons too large to use cartridges, the problem was solved by the development of the interrupted screw.
 Later Developments
breech-loading became more successful with improvements in precision engineering and machining in the 19th century.
Although Kotter's designs were a marked advancement they were not fully adopted until the invention of smokeless powder by Antoine Lavoisier in 1800