I think the 125-140 grain give the best combination of expansion and penetration at .38 +P velocities. I'm sure a 158 grain bullet would 'do the job' but can't quite reach the expansion velocities. I'm not saying it wouldn't be effective because they will likely penetrate to beat the band. 110 grain bullets may be a little light, but at the higher velocities they would penetrate and expand with no problem. I'm kind of amazed at what a small, fast bullet can do. I don't think I'd be charging my victim after getting hit by any .38 +P round.