Can I Shoot .38 Special in a .357 Magnum Revolver?

Designed to Work Together

The .357 Magnum was developed in 1934 by Elmer Keith, Phillip Sharpe, and the Smith & Wesson team as a more powerful evolution of the .38 Special. From the beginning, .357 Magnum revolvers were designed to chamber and fire .38 Special ammunition.

The .38 Special runs at a SAAMI maximum average pressure of 17,000 psi. The .357 Magnum generates 35,000 psi — more than double. Firing .38 Special in a .357 Magnum revolver that is rated for the full 35,000 psi load leaves enormous pressure margin. There is no overpressure risk in any direction.

The .38 Special case seats in the .357 Magnum cylinder and fires exactly as designed. The bullet exits the cylinder gap and into the barrel. The only difference is a small amount of gap at the front of the cylinder chamber where the shorter .38 case ends.

Why the .357 Case Is Longer

The .357 Magnum case is 0.135 inches longer than the .38 Special case. This is intentional. A .357 Magnum cartridge is physically too long to fully seat in a .38 Special cylinder — the cylinder crane will not close. This prevents a shooter from accidentally firing a .357 Magnum in a revolver not designed for the pressure.

The length difference makes the two cartridges one-way compatible by design: .38 fits in .357, but .357 cannot be forced into .38.

Carbon Ring in the Cylinder Throat

When you fire .38 Special in a .357 Magnum cylinder, the shorter case does not extend to the front of the chamber throat. Combustion gases deposit carbon fouling in the forward portion of the cylinder throat — the area that the .38 case does not occupy but the .357 case would.

This leaves a ring of carbon buildup in each cylinder throat. When you switch back to .357 Magnum — which has the longer case that extends into that area — the carbon ring can prevent the .357 from chambering fully, or cause accuracy issues as the bullet transitions from the case into the cylinder throat against the buildup.

How quickly the ring builds depends on the volume of .38 Special fired and the specific powder and bullet combination. Soft-lead cast bullets with faster powders tend to foul more. For most shooters who alternate between both calibers, a cleaning before switching is sufficient.

How Shooters Use This

The most common use case is cost-effective training: .38 Special ammunition is typically cheaper and has noticeably less recoil than full-power .357 Magnum loads. Many shooters practice with .38 Special and carry or hunt with .357 Magnum, running the same revolver for both.

.38 Special is also the standard for cowboy action shooting (SASS) and revolver competition, where revolvers are routinely chambered in .357 Magnum specifically to allow .38 Special competition loads.