.40 Caliber

.40-70 Maynard 1873

.400 Holland & Holland Magnum

Introduced in 1961 the .401 Herters PowerMag was the creation of George Herter. George had the foresight to see the growing interest in a single action revolver chambered in modern large bore magnums. Seeing a need for a more powerful cartridge than the successful .357 magnum but with less recoil that the powerful .44 magnum, George developed his .401 PowerMag. He contracted with Sauer & Sohn of Germany to manufacture a copy of the Colt single action revolver chambered in his cartridge. The PowerMag revolver was well made and exhibited the excellent workmanship of Sauer & Sohn. The PowerMag soon developed a strong following, which got the attention of Remington. In 1964 Remington introduced the .41 Remington Magnum with similar proportions and ballistics.

Charles Newton was a firearms enthusiast that was a pioneer in the development of high velocity cartridges. His noted accomplishments lead to the creation of the .22 Savage High Power, the .250-3000 Savage, the .25-06 (25 Newton Special), .256 Newton, .30 Newton, .35 Newton and the .40 Newton. While he was not the first developer to produce high velocity cartridges he is one of the pioneers and he did influence Weatherby and others in their cartridge development. Of all the calibers he developed only the .22 Savage High Power is still in production today.