Concealment of a large frame pistol or revolver is mostly a matter of personal comfort and the manner of clothing you're willing to wear for concealment. There are just so many good quality holsters available nowadays, although pistols tend to receive more attention from the holster makers than revolvers.
I've carried large revolvers concealed off & on over the years. S&W 629 6 1/2", Ruger Redhawk 5 1/2" and S&W 686 4", Ruger Super Blackhawk 7 1/2", just to name some of the larger ones. The 686 was an issued weapon (replacing my earlier 66), so I carried it quite a bit, and mostly with one of the common, "inexpensive" IWB holsters of the day. Shoulder holsters were useful for the larger revolvers.
Of course, I've often also carried smaller revolvers with 2", 2 1/2", 2 3/4" & 3" barrels, but I did still carry larger framed revolvers as off duty weapons. Not very often nowadays ... and mostly for personal comfort reasons.
With the right holster and clothing, and some willingness to accept a bit of personal discomfort in some circumstances, larger revolvers can be carried lawfully concealed ... especially in colder weather when wearing thicker cover garments.
Smaller pistols & revolvers are often easier to carry, though, and more comfortable, as well.
Yeah, I know, I know ... many trainers & ordinary folks like to quote the old quip about handguns being meant to be comforting, and not comfortable. But when you're wearing one for your job, day & and day out, 10-18 hours a day, after several years you may sometimes desire a bit less artillery and a bit more personal comfort on your own time. If you're expecting to go into Harm's Way, and you have no choice in avoiding it, that's one thing ... (and why I carry a carefully maintained 870 in my unmarked car's trunk, and will probably have to soon carry the rifle assigned to me, as well) ... but if you're going to be spending the afternoon with the fellows on the golf course, or dining and dancing with the little lady, or spending an evening with the fellows at the cigar lounge? Well, personal risk assessment and personal choice come into play, and your perceived "needs" may be different from mine, or some other folks ... and there's nothing wrong with that ...
One thing you might consider, however, is whether your choice of lawfully concealed handguns affects your ability to accurately & controllably shoot whatever you've chosen. Many folks seem to express an opinion that they can more easily, controllably and accurately shoot larger framed pistols & revolvers ... and some claim that one design is "better" for them than the other, meaning revolver versus pistol. I think that this might be a more important consideration in selecting a CCW or off duty weapon than mere "caliber".
If you can shoot a L-frame revolver better than a G17, there's that ...
If you can shoot a L-frame revolver better than a J-frame, then there's that consideration ...
If you can shoot a G17 better than any revolver? Well, then there's
that ...
Capacity-wise? Well, I just wish that S&W had been producing their 7-shot & 8-shot .357 Magnum revolvers back when I was carrying a wheelgun on duty. I wouldn't consider myself "under-equipped" if I was carrying one of the new 627 5" 8-shot .357 revolvers for a uniform weapon, or one of the 686+ guns with a shorter barrel (and preferably iron sights
) for plainclothes.
Caliber "power"? Well, that subject has been debated endlessly ... and will continue to be ... and all I'd offer is that once you've selected
your preferred defensive handgun, for
your perceived needs ... then you should do some research and select the best ammunition available which would suit your needs. There's a lot of good ammunition available nowadays, and more coming out all the time.
The suggestion to browse among the threads at the Tactical Forums, specifically in the Terminal Effects Forum, is a good one.
You should've heard the derisive comments I used to endure when I occasionally carried a Ruger Blackhawk SA revolver (chambered in .44 Magnum or .45 Colt) off duty. Too slow to reload ... too difficult to shoot ... obsolete ... antiquated ... not tactical ... etc., etc.
Until a couple of the guys watched me qualify with one of them, and place a fist-sized group on a target 1-handed & 2-handed, in the same qualification course, as fast as most of the regular folks were able to shoot their 9mm pistols, and faster than many of them. Sure, they're slow to reload ... but the first 6 rounds seemed okay.
Of course, as things would go, the head rangemaster later had the policy amended to exclude SA revolvers from being acceptable as off duty weapons.
I guess I'll have to wait until I retire to occasionally carry one again.
Anyway, I don't feel that revolvers are outdated when it comes to defensive CCW & off duty weapons ... but I carry pistols more often than revolvers, and when I do carry a revolver it's usually a S&W 642-1 or a Ruger SP-101 chambered in .357 Magnum. Otherwise, it's usually a 9mm, .40 S&W or a .45 ACP pistol, and a compact or subcompact, at that ... and then it's most commonly a 9mm (3913, CS9 or a G26 ... and soon to be a SW99 Compact 9mm). I've got a respectable collection of full size pistols, too.
Personal choice is a wonderful thing ...