As I understand, gun laws vary a lot between States in the USA. The UK I believe has very very strict gun laws. I thinks extremely hard to get a high powered rifle or handgun there.
In Australia (where I am) it varies a bit b/w States, even though they are supposed to be uniform. Handguns are difficult to get, and you can only get them for target shooting. I think (I do not shoot pistols) that any calibre >38 is banned.
It is no more difficult to get a 458 Win Magnum rifle than it is to get an air rifle or shotgun. Semi autos are banned. Pump action shotguns are banned (so you cannot have a 12ga pump, but you can have a 30-06 pump )
The process is:
Take a firearms safety course and test (run by Police in Victoria)
Fill out an 8 page application form, supported and signed by your spouse and a responsible person in the community
Show you have a genuine reason for wanting one (Being a member of a shooting/hunting club is not compulsory, but helps get things thru)
Pay the fee.
Each time you want to acquire a firearm fill out a form and demonstrate reasons why you need it (not as bad as it sounds, I need a 12 ga skeet gun, 12 ga trap gun, 12 ga duck gun, 20 ga quail gun, 410 for general practice, 22 for target, 22 for hunting, spare 22, 22-250 for foxes, 270 for pigs/goats, 30-06 for hog deer, 338 win mag for sambar deer, plus a 308 general purpose as a spare.
I don't have all these, but I could.
If you have more than 6, the police knock on your door sometime without warning to inspect your storage facilities (there are minimum standards).
_________________
I just dropped in to see what condition my condition was in.
Strewth!