And the answer is the 12 ga. slug - well, make it a 10 gauge just to be safe...
The only pistol cartridge I know of they both agree on is the 41 mag. Silvertip ( and up ). Oddly enough, I just happen to have 3 4" Smith 41's and a coffee can full of speedloaders, say a dozen apiece for each gun.
My serious social work rifle is the FN49 in 7x57 with softpoints and 175 grain ball. Just like the ammo Karamojo ( WDM ) Bell used. LOL, it's true! You think that's a little light and I should move up to a heavier caliber?
Marshall/Sanow says one thing.
Firearms Tactical and Facker say another thing.
Before them came Skeeter Skelton, Elmer Keith and Bill Jordan allowed a 200 grain 40 caliber slug and a thousand feet per second ought to do. That's how we got the police loaded 41 magnum - bout the time these newfangled hollowpints ( Lee Jurras' Super-Vel leading the way ) hit the market.
o-town, sorry to make fun, but it's so frustrating to try to get a straight answer. You either scream or laugh. If you find out the answer, post it back here. I got a couple 380s I want to keep handy for when it's inconvenient to have a real fighting handgun on me.