Caliber I am not so concerned about because let’s face it a gut shot animal is still a gut shot animal, doesn’t matter what caliber it is. Accurate shot placement is key.
Well, a few things on Caliber: Capacity is an issue, and .45 just doesn't have it. IDK if you ever wrapped your mitts around a double stacked .45, but you better have big ones. Shot Placement depends on hand weld. With a shoulder stock, you can add cheek weld, and shoulder weld. That's one of the primary reasons why I favor the (Chinese contract) High Power, I have 2 more points of contact to hold the sites steady, and hit what I'm aiming at.
I Double Tap. 1911 fans point out the 1 shot stop statistics from the FBI's own "Stopping Power" study, but that's assuming 1 shot. I'm not assuming 1 shot, and 9mm is right around the butter zone, where you can double-tap accurately, and still have decent terminal ballistics (Penetration, Expansion...) Which is probably why it's a military standard for just about everyone, including the yanks, and not the .45. It's not twice as effective as the 9mm Luger. So, for my money, I'd rather have 15 shots of that than 8 shots of .45.
10mm/40S&W is actually a more refined (By Jeff Cooper) modern round, with regards to packing the most efficient firepower into a grip magazine. That's literally what it was designed for. However, I can't buy either of those by the 5 gallon bucket, to shoot 500 at a time, as quickly as I can load them in the pez dispensors. Which goes back to Shot Placement. The only way to get good Shot Placement is to shoot your guns, enough times to make it second nature. You don't have to compete, but if all you've ever done is punch paper, and analyze the groups, the nominal MOA of the firearm is meaningless if you're sitting down, just ran 3 blocks, or are jumpy because when you put on your holster that morning, you weren't actually expecting gunshots to erupt behind you.
This is why I stress that it's not an Amulet of Protection. The inverse to the "Guns don't hurt people" argument is that they don't protect you, either. You protect you, and your property. The gun isn't going to do it for you, no matter how accurate it shoots in the Bench Rest. You have to be capable of accurate shooting under stress. You're not going to be attacked, on the street, nor in your home by a paper target, at a measured range, with a chance to prepare. You won't have Hearing Protection unless you thought to include it, with your legal length tacticool black side saddle accuratized shotgun.
It's going to be a stressful situation. If you can't shoot under stress, you're probably going to die with your guns, anyway.