135gr Speer Gold Dot short barrel 357 magnum vs. 135gr Federal +P Tactical Bonded 9mm out of snubby revolvers and micro semi-auto with a 4” compact thrown in for reference. Left to right: MP340, LCR9, P365, G19x 357 Magnum Peak dB at shooter ear 170.2 The 9mm +P Federal is slower out of the LCR9, but much quieter and softer shooting. 161.5dB instead of 170... it’s a noticeable difference. Velocities with the P365 were almost identical to the LCR9. Just a whiff louder, but within measurement error at 163.4dB. What barrel length would bring the 135gr +P 9mm to the short barrel 357 magnum velocities? With a 4” barrel, the 9mm was faster. I’d guess that velocities out of a G26 or G43 would be similar to the short barrel 357 magnum. Conclusion: for commercial 357 magnum out of a snub, it’s about subcompact 9mm power, both in this current 135gr and the previous 124gr test. Sure, you could load hotter 357 magnum... but the 9mm revolver is quieter and more easily shootable. I think I would take that trade off. I’m still favoring the LCR9 over the MP340 loaded with 357 magnum. Of note: the 135gr +P 9mm Federal didn’t fully expand out of the revolver, but it did out of the P365 (at similar velocities), so there’s something destabilizing potentially with that combination. Left to right: P365 (12”), G19x (12.5”), 2 shots from the MP340 (14”, 14.5”), 2 shots from LCR9 not fully expanded (15.5”, 15.75”), Please “like” if you found this informative!