Hi Cameron,
Without knowing your level of experience with firearms and ability to reload, to afford more ammo, etc, I would suggest something more conventional than the 454 revolver. The 454 is a monster, heavy weapon, heavy recoil, expensive ammo. If you only shoot occasionally the big recoil of the 454 could cause a flinching situation where your shooting skills suffer.
I suggest you try to shoot as many centerfire weapons as possible until you find one that suits you the best, has common ammo, and is 100% reliable. A good revolver choice would be a S&W 28 Highway Patrolman - is is a large frame 357 that will outlast your grandchildren if well cared for. If you are on a budget and don't anticipate hunting bears then a plain old police revolver in .38spl or .357 would be just fine despite what many on this board would say. Ruger, Colt, S&W are fine, I would avoid knock offs if possible. And you would be able to save the rest of the money to set up to cast bullets and reload.
If you decide for a semi auto pistol, anything is good from high quality makers like Glock, Sig, SA, HK, S&W, etc. I chose the Glock 23 since the FBI really tested them and i've grqwn to trust then without question. Don't get carried away with the 'more expensive must be better' - I've carried a few different weapons on the job and the pricier Sigs don't have all the features of the Glocks and our duty weapons were recalled a couple of times for springs and pins.
Also, please keep an open mind to pocket pistols such as the Beretta Jetfire, NAA mini revolver, etc, although they aren't impressive and powerful, they can be with you just about all the time in non-survival scenarios when you are legally able to carry. Trappers like small weapons like that for dispatching game and it sure packs better in your front pocket than a 454 Casull!!!
Regarding the .22 bolt action - excellent idea! If you shop around at shows you should be able to find old Marlin bolt action 22 rifles cheap that will shoot circles around the 'survival' rifles all day long! Single shots are fine for hunting and you don't have to worry about lost magazines or complexity. For under 100 bucks you should be able to set up a scoped .22 with a sling attached that will serve you quite well.
For a long gun it's just as open as anything else and depends upon your preference. I like my Mausers in 30.06, they are reliable, very accurate (1 MOA with my own cast bullets) and built to last many lifetimes. The '06 is a great cast bullet cartridge which can't be said for many modern cartridges. The .303, 8mm, 7mm, etc are also great but not classic American calibers so ammo will be available on a so-so basis. The 30-30 is a super cartridge for bullet casting as well, only issue I can see is that the action type isn't as durable as a military turnbolt. Just go to a gun show and check out well used military bolt actions against old lever rifles, the lever guns will wear sooner although for most shooters the issue is null.
Mausers are extremely reliable due to the camming action applied to the case when cartridges are extracted and loaded so they won't fail as readily as a semi auto but again, semis are used all over the world with great success so we are splitting hairs here. You should be able to set up a surplus bolt action with lee loader for under 200 bucks. A used lever gun will require full length casae resizing (reloading press) and the whole thing should be less than 300 bucks if you shop on EBay for your reloading gear.
The military rifles are a little expensive and more regulated in some areas but some designs (AK, FAL, HK, and to some extent, the AR15 family) are tried and true, if that's your thing and you are willing to familiarize yourself a bit more than they are good too.
Finally, the shotgun is something that can protect you, provide game, and is the best overall long weapon available with minimal training. A pump action would be very good and affordable - I have seen used Remington 870 Express models go for under 140 bucks and, with a slug barrel, are really all you need. Reloading is a snap with an old LEE shotshell loader from EBay that will fit in a shoebox with powder, primers, wads, and some shot (the wads and shot are bulky/heavy perspectively). I prefer the Remington 870 but the Mossbergs, Ithaca 37, Winchesters are just fine. Again, it's your preference, just avoid oddball versions and shoot the heck out of them to make sure everything works (Ithacas develop weak followers, Remington Shell latches go bad, the others develop issues as well). Buy new ones if you can afford it or learn basic repair from an AGI video or some other resource and repair your own if you are mechanically inclined.
Overall, pick the weapon that works best for you and develop talent with it. Don't wory about impressing anyone with it as a show-and-tell item - most survival type weapons are about as glamorous as a pipe wrench.
About shooting - Not to say that there aren't great mentors out there that instill excellent shooting values among their children, but the worst and most unsafe shooters I won't shoot with are 'experts' on firearms and were taught to shoot by family members. I have been at informal shoots where all kinds of really stupid things happened and I'd rather not be there again. Just learn to be a safe and accurate shooter and seek professional training if you are a beginner.
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Be Happy