.357 SIG is a criminally underrated round with a fair amount of misinformation surrounding it, the most common being that it's really no better than 9mm +P or +P+, but the reality is that as long as it's not being downloaded, it not only leaves 9mm +P+ in the dust, but will rival anything but the hottest .357 Magnum factory loads.
Does it lose velocity out of shorter barrels? Of course, but between your typical 3.5" and .4.5" barrel the amount of velocity lost is negligible at best, maybe 50fps on average.
Granted, I've heard rumors that factory loaded .357 SIG has been loaded a bit weaker over the years, but I'm not convinced that it's accurate when the closest thing to "proof" I've seen is cheapskates on YouTube shooting a single round across the chronograph in the dead of Winter and comparing it to the results of an older video which was filmed over the Summer a year or two earlier using a completely different chronograph.
Not to go off on a tangent here, bit it annoys me to no end when folks decide to cheap out on ammo tests by only shooting a round or two at most, then calling it good enough. Make it a proper 5-shot average or don't bother. It's like, I know .357 SIG ammo is expensive, but it ain't THAT expensive.
Last but not least, I'd hate to go there, but... There are folks online who carry 9mm yet are evidently extremely insecure about it, so they feel the need to reassure themselves that it's not only perfectly adequate for self-defense, (which it certainly is) but the absolute best round available and that everything else is somehow inferior. These are the folks who seem the most apt to push the narrative that .357 SIG is no more powerful/effective than 9mm, yet somehow inexplicably manages to produce harsher recoil, concussion, and report. So these folks will happily cherry-pick any bit of information they can to push their narrative and therefore they'll jump all over the cheapskate YouTube single round ammo tests with underwhelming results.
