38 Special is too weak using today's loadings and 357 Magnum just shoots a wimpy little bullet just a bit faster.
Search up THE LOAD to see some hotter 38 Special loads. Ignore all the whining, sniveling and hand-wringing.
You may as well go with heavy bullets if the gun only holds six rounds. I really like 44 Special. You can duplicate 45 ACP or get some hotter loads that top what 45 ACP can do. I recommend a Ruger Alaskan, S&W Model 624, S&W Model 24, S&W Model 29 or S&W Model 629. You can shoot 44 Special out of all of them and you can move up to 44 Magnum in those guns chambered for it. I find the 44 Special defensive loads to be pleasant to shoot. Factory 44 Magnum is not so much fun, but it can be downloaded.