[Byron Quick]

Is there any reason you can't use .38 special bullets in a .357 case?

[PaulS]

Byron,
NO reason not to, they are the same diameter.

PaulS

[Quantrill]

Byron,
They are the same diameter so can be used. However do not use the .38spec load data in the .357 case. Use data developed for the bullet in the longer case. Usually the powder charge is a little larger to make up for the increased space. Quantrill

[Standing Wolf]

However do not use the .38spec load data in the .357 case. Use data developed for the bullet in the longer case. Usually the powder charge is a little larger to make up for the increased space.

I've been using .38 special loads in .357 magnum cases for decades with no ill effects or loss of accuracy. When you put 2.7 to 3.1 grains of Bullseye in either case, you're going to end up with quite a bit of air.

[labgrade]

Some .38 JHP bullets are designed to expand at the lower .38 velocities & may not penetrate as desired at higher .357 due to over-epansion. Just a thought.

Too, most certainly don't use .357 data in a .38 case - but you knew that.