Are they the same?

or are they
A. not the same but very similar
B. totally different


not talking about the whole cartridge, just the projectile

357Sig bullets are 9mm in size(.355-.356) where as, 357Mag bullets are 38Special size(.357-.358in.).

This a generalization, but in the ballpark.

As noted they are 9mm BUT, work up your load & 0.357" jacketed bullets can be used. I shoot 0.357" coated lead bullets in my 9mm.

thanks for taking the time

I personally feel you are walking on egg shells by using .357 bullets in a caliber calling for .355. The pressure is high enough all ready.

quote:

I personally feel you are walking on egg shells by using .357 bullets in a caliber calling for .355. The pressure is high enough all ready.

If you work up your load, it isn't a big deal. Yes you need a chrono to see where you are going but certainly can be done.