But you need to also stipulate that you are talking about handguns of similar action and weight. I can shoot a 9mm faster than a 40 S&W in similar full size handguns but the differences are measured in very low .01 seconds in most shooting situations. If I was to compare my splits between a sub-compact 9mm and a full size 40 S&W the 40 S&W splits will be faster. For that matter I can shoot most of the 40S&W pictured up thread (including the revolver) considerable faster than my little pocket 380. It may be true most can shoot 9mm faster than 40S&W but only if comparing similar guns, the differences in recoil though real can be trumped by weight and size fairly easily.
That is what I found.
I've compared using a Glock 19, 23 and 32 using
carry ammo (+P in the Glock 19)
I speculate that most who compare 9mm to 40 do so with target ammo (FMJ)
115 FMJ does not have the same recoil as 124/147 HST +P but 180 FMJ 40 S&W recoils like 180 JHP.
Someone comparing 9mm vs 40 S&W using regular FMJ but then loading the 9mm with +P for carry didn't compare fairly.
The only way to compare fairly is to use carry ammo to obtain split times.
Using carry ammo (+P in the 19) my split times were .03-.04 slower with the 23/32 than the 19 -
and...
That was with an accuracy component, shots had to hit a 6 inch circle at 6-7 yards to count. (Not just anywhere inside a whole silhouette)
I know that by carrying my Glock 32 instead of the 19 I'm about .03-.04 slower
(insignificant IMO) on follow up shots with equal accuracy.
I sacrifice two rounds capacity, which is tangible, but in return the bullets have better ASAP incapacitation potential.
If fractions of a second matter in follow up shot times, we can't discount benefit of stopping an attacker potential seconds quicker.
Averages from my pistols:
Glock 19 - Federal HST 147 gr +P @ 1,044 fps / 356# KE
Glock 19 - Federal HST 124 gr. +P @ 1,210 fps / 403# KE
Glock 23 - Federal HST 180 gr. @ 1,003 fps / 402# KE
Glock 32 - Federal HST 125 gr. @ 1,358 fps / 512# KE
357 Sig has at least 21% more KE than 9mm+P
Someone might say KE doesn't matter, compare performance in gel, show gel result to be same...
okay.
If one thinks KE doesn't matter, I've got an example for you.
https://www.luckygunner.com/labs/revolver-ballistics-test/
Near identical performance in gel, looking just at penetration and expanded diameter...
4'' barrel 38 special Rem 158 LSWCHP+P - 13.4'' / .56
4'' barrel 357 mag Rem 125 SJHP - 13.6'' / .54
If one thinks additional KE doesn't matter then those two bullets have equivalent ASAP potential. (I think not.)
Same performance in gel but ...
38 special load has 298# KE
357 Mag load has 602# KE