This debate brings to mind three historical events that changed policy with Military and LE.

The first was the ineffectiveness of 38 cal (9mm) ball ammo on stopping Moro warriors, hence the development of the 45 auto shooting ball ammo.

The second was the miserable performance of half a dozen FBI agents shooting high capacity 9mm autos with JHP ammo into two thugs in Florida (shot placement notwithstanding the scrutiny). Said firefight ending when one of the LEs pumped a few 12 gauge slugs in the uncooperative crooks. Shortly thereafter LEs were packing 45 autos.

Army decision to go to 9mm Baretta shortly thereafter instead of the tried and true 45 auto because the 9 was a more manageable sidearm in the less skilled, less trained hands of the new infantry and certain non-combatants. Hmm, less than 80 years after learning their lesson in the PI, they take the giant step backwards once again using 38 cal ball ammo.

The 10mm was a pretty good compromise. It had the down range trajectory and energy retention of the 357 mag full throttle loads, but the mass and smack more approaching the 45. It would certainly slap you around, though. I think it was women LE who made the case for the 40 S&W, as the 10mm was just too much for them.

History has proven, time and again, that unless you get the 38 cals up to 357 magnum velocities, they just don't work as manstoppers, all things being equal. A torso shot from a 9mm just won't have the same effect as a similarly placed heavier 40. That's been proven and generally accepted as gospel amongst the professionals. Most of the LE departments I've worked with switched from 9 to 40 a long time ago and none have gone back as far as I know. Sure 9 is gonna be cheaper than 40 for practice, but I prefer to do most of my handgun range time with a 22 anyways, the skills are pretty much the same. As far as handloading goes, that is about the least important argument to be brought up in a self defense case. Either your shooting was justified or it wasn't, and those little nuances are trivial and won't be changing anyone's mind on the bench or in the box. They're gonna look at you and the only thing they will think is whether this person needed to be shot or not. You could've used a shotgun shooting slugs on him and that would've been far worse than any handgun. Whatever "pre-meditation" claim some dufus attorney is gonna throw out there evaporates when I say that I handload for economy, which is a verifiable fact, and not some legalese conjecture. Juries and judges prefer facts to assertions.

The only seal I know much prefered a hush puppie 45 as his sidearm. 9mms don't do nearly as well at subsonic loadings.