Topic is now open again.

For the OP, you've already received some excellent advice on calibers, rifles, flinching, etc. There are some people who only hunt with one rifle but most hunters have more than one rifle and caliber for hunting different types of big game animals.

You mentioned deer, elk, moose, and possibly black bear as the animals you anticipate hunting. Depending on what state you live in, you'll probably be able to hunt deer and black bear every year in your home state (deer and black bear seasons overlap in many states) and should think about what caliber and rifle would best suit your style of hunting, terrain, etc. for those animals since that would be a rifle you use every year.

For elk and moose, you would probably have to hunt out of state for those animals and probably won't hunt either or both of them every year. You would probably want a bigger caliber for both of those animals and it would be a rifle you likely don't use every year.

Between your dad and any of his friends who own rifles, you could probably shoot different calibers and rifles to get a better idea of how much recoil you shoot well with and where your limits are. Hopefully this helps some.