- Col. Wesson, the vice president of Smith & Wesson, led the project with technical help from Phillip Sharpe, of the Technical Division Staff of the NRA, utilized the company's existing .38 Special round with a different powder load and extended the case by 1/8th of an inch. Their goal was to create a bullet that would travel at a speed greater than 1,000 feet per second (the measured speed of the Colt).
- Idaho rancher, author, hunter and firearms enthusiast Elmer Keith is credited with some of the early development of the .357 Magnum due to his experimenting with the Colt in increased pressure levels. He took .38-caliber revolvers and built them on .44-caliber frames. He experimented with borring the gun cylinder to a caliber of .357 while using a .44 Special size gun.
- Due to the gun's barrel, cylinder and frame being stronger than the standard .38, it was able to withstand higher pressures. A .357 Magnum has about twice the pressure of a .38, though the cartridge is very close to the same size in diameter. Early .357 cartridges could be placed within a .38 gun since the case was about equal in length.
- Elmer Keith is credited with coming up with the idea of lengthening the case by 1/8th of an inch so there was no way a high pressure .357 cartridge could be placed within a .38. Keith is also famous for the "Keith-style bullet" that increased a bullet's cutting power while moving through a target or body. He put more mass of the bullet outside of the cartridge, allowing more room for powder.
- The Keith-style bullet was the base of developing the type of bullet for the .357 Magnum cartridge. It was built of a hybrid of the Sharpe bullet's shape and the Keith bullet's bearing surface. Today, the .357 Magnum is not very popular among police, army and government entities due to the lighter, more high-capacity, semi-automatic pistols that are currently on the market. After nearly 80 years, it still remains popular as a gun for self-defense and hunting.
