Like the 38 Special, the 357 Magnum fires a 0.357-caliber bullet, but there are two main differences. The 357 Magnum’s case is 0.135-inch longer, and manufacturers load it to a MAP of 45,000 psi.

The 357 Magnum’s longer case prevents 357 Magnum ammo from being loaded in 38 Special revolvers, but it’s the difference in pressure that truly sets these cartridges apart. The 357 Magnum can ...