When we choose a holster we think we're just picking something for our pistol. When really we should be choosing our pistol to fit the space we have available to carry it!
A Galco. For God's sakes, don't do this -- in a 2-1/2" barrel (it's a K frame, see the flutes?) and the cylinder being fully above the belt, there is not even a long barrel to offset the loss of balance. Someone's going to have to sell you a 'good gunbelt'.
Sure, many out there have their pistol chosen for them, by their LEO employers. And even where they'll wear it. And what they'll carry it in. This post is not for you; you're screwed if your chief has made a decision of expediency vs. one of knowledge.
WTFs, I call these Safariland 'holsters'. Put a paddle on a house brick and be done with it.
For the rest of you, KIS -- keep it simple"
First: if you have one of these pistols (below), a Baby Browning so small that it's practically a key fob or a bracelet charm, you aren't meant to holster it. They were/are vest pocket holsters, literally. In such a pocket you could be expected to make some sort of reasonable draw without fumbling it; and unlike a Glock it has plenty of active safeties to keep you from shooting the wrong thing at the wrong time. MUCH smaller than Bond's Beretta, for example. But neither is for a belt holster, an IWB holster; maybe an ankle holster? When you're wearing shorts or a skirt? Not an option anyway.
Second: if you chose a .380 auto or a 2-3" barrel revolver, wear it anywhere you like. They're all light so the holsters for them are also compact; choose a belt holster or a shoulder holster or a whatever holster. I'll speak about gunleather for them in a moment.
The fictional James Bond used both these pistols after his Beretta. Ideal for concealment including in a shoulder holster: lightweight frames, low ammo capacity, up to .38 holes in their barrels, short barrels and short grips; easy decisions for pistol packing by real people.
Third: if it's a larger pistol, in which case the 4" K frame and the 1911 auto are in the same class, don't forget that these are typically steel-framed. And if you think you got clever by choosing a polymer-framed Glock, think again: the revolver holds 6 shots typically, but the Glock three times that. Lots of weight, all concentrated at one end instead of in the middle as with a revolver. Unbalanced; and now you have not only weight challenges for a shoulder holster, but balance problems for a belt holster. And the big grips just add to the problem that you're going to blame on the holster maker anyway.
This one was Bill Jordan's original .357 Combat Magnum, which he is credited for inspiring yet Hank Sloan had his .357 Combat Masterpiece earlier that same year (same frame).
Fourth: if you want to carry your N frame Smith or a Ruger Redhawk, by all means. But don't jump onto forums bragging about how you carry yours IWB; you're an idiot. These are hunting guns and created (if gun makers actually think at all about how their products will be carried, which they don't) to be worn at the waist; and thanks to gunleather designers can be carried really well across the chest in a bandolier holster. The barrel is long and for good reason: accuracy with iron sights; and one simply can't miss with a scope. You also get increased muzzle velocity with the longer barrel. 3" N frame in .44 Mag? Thank God you don't have to shoot it as much as you carry it; dumb and it doesn't make you a Master Blaster. What are you gearing up for, some imaginary Apocalypse?
Jelly Bryce carried a revolver like this one, on his hip in a Myres Threepersons. "Just like my Smith .44 Mag!" Not really; his 3-1/2" barrel is in .44 special and has small grips: concealing it and shooting it were VERY different to carrying and shooting your sawed off .44 Mag. And he could put five shoots into the center of a man' head in seconds with it: recoil control.
Fifth: have electronic sights or a scope on your pistol? Adds weight, adds bulk, only ideally suited to competition events and hunting. Flashlights on the underside add a target for your opponent to shoot at and create a void around the trigger to help neighborhood littlies fire your pistol for you; all that's your business but dunno why you'd volunteer for it. Put it on your belt or in a bandolier holster.
If all the above seems simply argumentative, then consider these examples of GOOD choices you can make:
Now; for some reason you've decided you absolutely want a shoulder holster. They have their pluses and minuses, with the pluses focused around how easy one can get them on and off as you move from situation to situation; and you can wear them with any clothing -- shirts, skirts, shorts and bathers; as long as you're wearing a shirt/blouse. Bottomless, even, if you don't reckon you'll attract far too much attention for doing it. But you must choose a small pistol or be completely dissatisfied; and you'll blame the designer/maker if you don't:
Shoulder holsters naturally flip the grip outwards as they hang. Using a big pistol like a 1911 or K frame simply makes this worse; at least the real actor above is carrying only a PP (better with a PPK as intended by Fleming). So pick a shoulder set only if you've small pistol.
"I've got it", you think to yourself, "a horizontal shoulder holster!". Sure -- if your pistol is short enough. A big chested man, or a big bosomed woman, might get away with up to a 4" barrel; but not the rest of us. The pistol is just too long for the typical wearer. You don't realize this when you make your purchase because we designers create these holsters to be barrel-tolerant (the muzzle of the holster lets you put a Buntline Special in a horizontal if you want to) but reality intrudes on long barrels. They're meant for short barrels only, and you won't like even that if the pistol is not lightweight, too:
"Me like", you think of the above. "Me no like" you'll think of the below Seventrees of 1969 it's just too damned long (notice how far ahead of the very long barrel the harness has been attached; now it's all sticking out the back of your jacket):
Now, having chosen a bigger pistol for firepower, like a 4" .44 Mag to use the extreme, you'll want a belt holster. If you choose an IWB you'll have much leeway about ride height; but dammit they're so bulky and heavy, why do it at all. Let's expect that you'll choose a belt holster, instead but don't choose this topheavy monster from Galco:
Choose this reasonably well-balanced holster (below) from them instead. The weight of a single stack magazine is above the belt, the long barrel/frame rests against your hip/pelvis and creates balance:
No worries, you'll just 'get a good gunbelt'. Don't; be smart instead and choose your holster wisely. Don't rely on your belt which practice became the standard when Roy Baker popularized the too-high-ride pancake belt holster a half century ago (he was a saddler then a hardware maker; what they Hell did he know about gunleather function?):
Competition shooters of the '70s -- and they still write for gun magazines today -- made all this worse because they used the gunleather originated in the 1960s for fast draw. Big, heavy, thick, steel reinforced. They didn't/don't know any better. Then holsters became 'practical' but they kept wearing their Alfonso trousers belts that were more than a 1/4" thick and never looked back.
You want to carry a big, big gun. A Redhawk, or you have an old Automag, or a scoped Smith .44 with 8-3/8" barrel? Choose a bandolier holster but not an underarm shoulder holster like a Bianchi X15.
Bianchi's HUSH system (above) that I created for them; it's nonleather for good reason. All that weight and bulk is ideally distributed across the torso, and it hides under hunting coats (from the elements). Below, though, is an X15 with a big gun; awkward, heavy, unbalanced, the spring grabs at every part of the pistol and tears up the leather inside:
Dirty Harry was fictional; you don't want to carry all that weight under one arm as above.
Nope, put these big guns across your chest, or down on your hip: