Mt first handgun was (and is) a Smith & Wesson Model 28 Highway Patrolman(5th picture down). Very comfortable, especially with Pachmyar grips. You can run .38 through it for cheap plinking, and full-load .357 for louden-boomin-noisen. By the bed, it is loaded with Glaser Safety Slugs.
How much do you give up in such a short barreled gun as the model 340, which has only 1 1/2 inches of barrel? That’s not a lot longer than the slug, fer cryin’ out loud. Surely you loose accuracy (which isn’t all that important for the purpose of that gun), but I wonder how much “stopping power” the OP is asking about is lost.
That’s what I meant to say, not the old Rhino’s I used to run. The Glaser is less likely to go all the way through the house being able to be stopped by drywall and lumber, but will do a real nice job on “softer targets”. I use the Hydro-Shock type in the 9mm due to penitration ability for car doors or windshields but still has the hollow point benefit.
Thanks
I doesn’t affect the stopping power/impact, only the accuracy. The longer the barrel the more rifled bore and spin and thus, more accuracy. Most short barrels are for the up-close-and-personal type of encounters such as the gunfight in the elevator referenced earlier. 
I don’t have a dog in this hunt, but I am reminded of the opening lines in the book When Eight Bells Toll By Alistar McLean.
IIRC the next line had to do with the Luger being a very ecomonical round, because if your brother was standing behind you, you could both be hit with the same round.
I’ve handled, several times but never fired, the shorty .50 Mag S&W. Supprisingly it wasn’t at all unwieldly. Heavy, hell yes, but it felt quite balanced and comfortable in my hand. Way too much gun for this city boy, and I don’t want one, but I plan to rent one soon at the range. I think it’ll be a kick (kick, get it?) ;).
For a revolver, for home defence, I’d pick a .44 Special. In general, autos are not good except in the hands of experts. If you forget- for that tiny second- to take the safety off, you’re dead, and your burglar now has a cool new gun. Now, for police, the auto is likely better, and the 9mm is fine- but if you prefer the .45 9as i do0 or the .40, then that’s fine also.
Good point about the safety. But many of the modern autoloaders do not have any external safety that needs to be manipulated. Glocks, Springfield XD series, Kahrs are the ones I’m most familiar with. I’m certain there are others. I own Springfields and Kahrs. It’s pretty much grab and go with these models.
For home defense, due to what I’ve learned here and from other sources, I’m very comfortable with my 20ga. But in the unlikely event I ever need to go out and take something with me, I’d like to have some firepower in a package that doesn’t attract a lot of undue attention. The S&W 340 and similar guns seem to me to fit those needs. No hammer, no safety, compact and powerful, and built for one purpose.
But I’ve got some shooting and soul searching to do before I decide what and if I’ll actually wind up with a “pocket gun”. It’s pretty serious shit to me.
mangeorge
Bricker, let me know if you want to go shooting. I have a nice little Argentine .45 that you might like, and it only cost me about $300 new.
Wise words to anyone. There are few things in day-to-day life that are more serious than this decision. Feel free to contact me here or via email if you have anything you’d like to ask. I’m not an expert, but I’m fairly well versed and experienced. If not me, most any of these good posters can surely help.
Good luck.
Pray for Peace, but keep your powder dry.