Dunno about South Africa but we can own firearms in OZ, they are just harder to get and the types more restricted than in the US. I've not got any yet but AFAIK it goes like this (I've shot plenty over the years but never got a licence so I'm prepared to be corrected about this if there are any Aussies here who know better)
To own a long gun you need to either join a gun club, own a property larger than 40 acres, or get a letter from someone who does own a property larger than 40 acres to the affect that you are allowed to shot on his property. Having got the letter you can shoot where you like. There are police checks that can take quite a while (months) for your first gun. Less I believe for subsequent guns.
For a side arm you have to attend a gun club for 6 months and jump through a few more hoops.
Open carry is not permitted anywhere public except where unavoidable like from the car to the gun shop/range etc but it must be in a case or bag or something, not in the open.
You can carry in the car as long as a person cannot see it (or anything that yells gun like a recognisable gun case) through the windows.
I don't think there is any limit on the number of firearms you own.
There are limits on the amount of ammo you can keep, but the exact number is not defined and it's up to you to argue that you need X number of rounds (depends on the state). So I'm guessing 5000 would be ok for a competition shooter or professional roo shooter but not for someone who shows no inclination to actually use the gun very often or even go to a range (AKA a STHF "hoarder").
Vintage firearms do not have to be licensed.
Semi-auto is allowed I think if you can justify it (not sure how you would do that, maybe if your job is culling pigs from a helicopter or some such).
Full-auto, no way for the average person.
As to when this all came about, the current restrictions were put in place after that arsehole Bryant shot 35 people at Port Arthur in 1996.
http://en.wikipedia.org/wiki/Port_Arthur_massacre_(Australia)
As usual the politicians knee jerked and implemented new rules. There was a buy back and after that if you had an illegal type of firearm you are in deep doo doo.
Before that things were much more open (although I don't know how open).
As to how many unlicensed guns are around I assume nobody knows but I was told yesterday that there are 90 million guns in Oz, now that's about 4 for every man, woman and child so I can't see that number being correct but I think it's fair to say there are a hell of a lot. OTOH a family was busted not far from me with over 30 (most unlicensed) and I know two people with around 30 guns each, so maybe.
