I wanted to share my experiences carrying medium to large size revolvers such as the Ruger GP100, S&W N frame, and Ruger Redhawk. I've found it much harder to find holsters for these revolvers that I really like. It should be no surprise that most of the holster market is for small to medium semi auto, and small revolvers. Yes there are lots of options out there that work decent for wandering out to a deer stand. There's not a lot out there beyond multi-fit, hammer strap hunting holsters. About the only multi-gun style holster I've found that actually seems to work good is the Hunter Arms versafit. It is a good design that rides well, but the basic hammer strap is useless for anything other than hunting.
Getting into it I've found one that I really like, and as of now I consider it the best full size revolver holster on the market. That is the A.E. Nelson #392. On the surface it seems like a basic leather holster, but they have all the right things in the right places. First off they make these things stout. A holster shouldn't be like a fine leather glove, it should be a secure gun locker. These are made of the thickest cow leather, and treated to become semi-hard. They do soften somewhat with use, but not a whole lot. Along with that the belt loop on these is equally stout. the entire back is a separate piece of leather making it double thick. One thing I've found with a lot of holsters is the belt loops sag out quickly. This almost always leads to a gun that moves around, or worse, flops around as you walk. These don't do that.
Retention is a very personal choice. I love myself a thumb break, and this is a great one. It seems that they use some kind of metal tab in the thumb break so it is like a lever. It breaks easy and quick. This is one issue I've had with a number of holsters. Either that tab is so flimsy you have to push it way over to break the snap, or the hammer strap part is such a poor fit you have to pull that way over before it finally hits the hammer to so you can pull and break the snap. This holster is perfect in this regard, it's really just like using a ALS style holster it is that crisp.
Pictured below are some of my holsters I have that are comparable. In the first top picture we have from left to right: AE Nelson 392 for a 4" N frame, AE Nelson 392 for a 5" GP100, (lower, middle) Simply rugged flapjack for a 5" GP100, (upper, middle) Lobo leather enhanced pancake for a 5" GP100, Lobo leather enhanced pancake for a 3" SP101.
I included the SP101 holster because it shows the differences I see from small revolvers to larger revolvers as far as holster designs. In this instance I love the Lobo Leather enhanced pancake holster for the SP101. It rides great, and it is designed so that it hides really well. It forms to the side of your body. My only complaint is that when I first got it, the thumb break was such a poor fit it was nearly impossible to break the snap. They fixed it at no cost, and it works well. I do wish the thumb break was stiffer, but I will say being softer it can ride right against your skin and never dig in.
Now compare that to the same exact holster but for the 5" barrel GP100. I hate that holster. I hate it so much I've never worn it outside of trying it on. At this size they become so huge that it is no longer concealable. It's like wearing a dinner plate on your side. The design of this holster is for 2" and 3" barrels. They don't adjust for longer barrels, they just make the holster longer. I even specifically asked for it to ride higher, and that's what I got. You will see in the bottom picture about how they ride with the belt loops lined up.
Also included was the Simply Rugged flapjack holster for a 5" GP100. It too faces the same problems as the Lobo holster, although worse. First off, the idea of the flap for the flapjack is horrible. Don't waste your money on that design. Either get the flap holster, or get the regular pancake. Second, this is also a design that is horrible with longer barreled revolvers. Actually the design is pretty bad all around. The hammer strap is not easy to use fast. The belt loops sack out, and no longer holds the revolver tight to you. Simply Rugged makes a quality holster, but the designs of them are just that, simple. They are at their best in small handguns with no retention at all. I can't speak to any of their other styles such as the cattleman, but their pancake holsters are best with small handguns.
Note how these holsters ride with the belt loops lined up. The Lobo is slightly higher, but not as much as the picture makes it look like. by my measurements on my pants, the Lobo has the tip of the holster 1/2" higher than the AE Nelson holsters. Both of the AE Nelson holsters have the same protrusion, because I asked for the 5" GP100 holster to be made to ride 1" higher than standard. The downside to that is you loose the cross draw loop, but I only carry strong side. The Lobo holster on the far right for the 5" GP100 rides a full 2" lower than the others. It does look like the Lobo's have more forward cant, but when on a belt they aren't that much different. Higher isn't always better with holsters, but so many are very low riders. The only other so called high ride holster I'm aware of is the Glaco Silhouette. I've never tried that one, but it doesn't look very good to me. i sure don't want my entire barrel sticking out of the bottom, not even if all my guns were stainless.
In conclusion, I think a pancake holster works great for smaller handguns. When you get to mid size guns there's no way you are going to blend that shape in with your body, it just wont happen. The best thing you can do is get a holster that is trim and hugs as close to your body as possible. I don't think you are going to be fooling anyone when carrying a full size revolver under a T shirt, but you can absolutely conceal one with something baggier such a a sweatshirt. Even as open carry I would never want anything other than a rock steady and well secure hold that the #392 has.