Looking into handgun calibers for hunting and bear defense and the .480 Ruger just seems absolutely perfect for most everything while still being relatively controllable.
Why is it not more successful?
Because it's not absolutely perfect. It's
ridiculously overpowered.
The ideal big game revolver caliber is somewhere in the .41 Magnum to .45 Colt (Ruger Blackhawk level). I chose a .45 Colt (Ruger Bisley) and a couple years into that experience I wished I'd got a .41 instead.
Reality is, handguns are generally going to kill best when thought of, and employed, as
glorified hole punchers, and a .41 caliber soft point or not-so-hard cast lead bullet, will punch a perfectly suitable hole in any big game animal, and allow its blood pressure to drop really quickly. And you'll be far more likely to put that bullet where it needs to go, with a .41 or .44 or .45Colt, even with little more than blackpowder level loads, than with a much harder kicking caliber.
Frankly a ~210 or 220 grain .41 or a 240-260 grain .44 or a 250-280 grain .45 bullet, with a decently wide meplat (~72% of bore diameter is close to optimum; larger meplats don't fly well at longer ranges and yes I'm speaking from experience) or even a basic jacketed soft point design or a Hornady XTP, at 1000' to 1200' MV, and no more, will *EASILY* ventilate the typical North American game animal with a big leaky hole. Said animal will then run 20-100 yards and fall dead.
Now, you absolutely can get a revolver (.460S&W for example) that will push a big handgun bullet well up into the good rifle-bullet-killing speed range and yeah, they'll kill like lightning. Like rifles. But you end up needing a halfway specialized handgun to do that, mainly because handguns are hard to shoot well past maybe 50 yards for most of us. When I had better eyesight 100 yards with a revolver was easy. Now, 25 yards is about tops, and I don't hunt with a handgun anymore. If it's something you want to do, do it while your eyes are young.
Everyone here knows the importance of low recoil for rifle practice. I'd argue that it's even more important with handguns, than rifles. Yes, shooting big boomers is fun. Been there done that, got the big goofy smile on my face. But if you want to get good with a revolver, you need practice, and lower recoil helps, and in a defensive situation where you're using something small enough to be easily carried, lower recoil helps with followup shots for sure.
I won't say anything about 9mms for bear defense except to say that's what I carry personally, for bear defense, in places with *black* bears, and I've only been in western grizzly country one time and still carried a 9mm. My intent here isn't to get into that discussion. I'm speaking of
revolver cartridges for dual use as both hunting handguns at revolver ranges, and also with a secondary role as defense. Yes, certainly you can take bigger calibers and turn them into longer-range killers, or get fast followup shots with a 9mm, but for the dual-role scenario you mention, the smaller .4x calibers with moderate bullet weights at moderate speeds, kill well enough, and are easy to shoot.
Something like a S&W 657 classic with a 4" to 5" barrel would be ideal for defensive carry, IMO, if you wanted it to double as a hunting handgun. If I wanted a hunting revolver to double for bear defense (same dual role, but reversed emphasis), I'd do the same, but with a 6" to 6.5" barrel instead.
FWIW I've shot a lot of Hornady XTPs and they penetrate very deeply at 1000' to 1200' impact speed but will expand violently once you get them up to maybe 1700'+, which I used to do often with a muzzleloader. On smaller deer at those 1000' to 1200' speeds you might consider Speer Gold Dots if you wanted more expansion but I've always ran under the 'glorified hole puncher' theory of handgun hunting.
