Many of the replies have dealt with rifle cartridges used in short carbines without shoulder stocks. I’d wager that most of them are outfitted with optical sights as well. When such a firearm is used afield, it is frequently fired from a bipod.
My 12 inch and 10 inch contender barrels are no more bulky than a 7.5" super redhawk let alone an X frame. The contender is no heavier, and in fact the super redhawk is often sighted with a low power LER scope. I carry my contender in a shoulder holster and a bipod would just get in my way. It is a pistol. Put a shoulder stock on it and let a BATF agent see you and see what happens. Yes, my favorite round is a rifle round, so?
.40/200/1000 is a good rule for momentum games like pin shooting or pepper poppers. It can't really be applied to hunting, not in modern times. Even in revolvers, there are rounds like .357 Magnum and Maximum which make plenty of umph for thin skinned medium game up to and including black bear. Actually, the .41 mag can be pushed to .44 mag energy territory if you handload and quite safely. I WILL have a .41 someday. I sort of like the cult calibers, hot .45, .41.
.44 mag is a fine cartridge, but it ain't got enough pizzazz. LOL!
I was reading about the .50 Wyoming Express, Freedom Arms's new load/revolver. I think the revolver manufacturers have finally reached the maximum of shooter tolerance. If .460 is hard to shoot, that .50 sounds terrifying. LOL! I think I'll give that one a pass. It is my ultimate goal when I get a little more income in a few years to get a Freedom Arms revolver, but I think I want a .454 Casull. That's enough, don't need to get ridiculous. LOL Mainly, I just like the revolver, very high quality and very accurate handgun in a powerful caliber that is not overly heavy like an X frame. Talk about your carbines! The X frame weighs more than many carbines. My contender is positively svelte by comparison.
Yes, I think energy is a better rule of thumb than bullet momentum. I think for our deer down here, an impact energy of 600 ft lbs is enough. Only the hottest .357s out to 50 yards really will make that. .44 mag, .41 mag, .45 Colt are not a problem. So, over 40 caliber really is better, but I'd push it well past 1000 fps for maximum range effectiveness. Thing is, you have to have complete penetration. Expansion on a flat nose bullet is not really necessary in my experience if you have a good, flat bullet. It will give a plenty good wound channel and a hole in both sides of the animal. What I like about the .30-30 contender is the rifle bullet, the BC, the fact that it carrys 1000 ft lbs (actually 960 I believe) at a full 200 yards. There is no arguing that one for effectiveness. It also offers a flatter trajectory than big bore pistol bullets. It's no less a handgun, just a one shooter that chambers a really effective round. I can understand the angst of calling a XP100 or that Savage (don't recall the model) a handgun. We all have our idea of what the definition of a handgun is, I guess, but I think of it as a gun that is carried in a holster. Those guns really are short rifles without butt stocks. I don't think of the contender that way. Oh, it took me a while to warm up to it, I'll admit, but once I got one, I couldn't believe I'd never owned one before. I mean, I think of single shot muzzle loading pistols as handguns, why not the contender? It is an amazingly versatile hunting system, too, with a selection of barrels to chose from.