In MOST of the US, there is no requirement to license or register guns. If they are not registered, there is no way to know how many there are. in 2004, it was estimated that private citizens in the US owned 192 million firearms- the number is higher now.
no possible way to know the answer with any accuracy at all.
72%
Too many
You need to tell us more about the "gun license" and for what area. There are many different gun licenses.
6
More than 60,000.
Gun owners aren't "registered" like cars. One estimate is that there are @ 4 million or so gun owners.
You can buy used gun safes in the US in many different places. Amazon and eBay are popular places that people often buy these type of cases at. Gun stores also sell used gun safes.
Depends on what you mean by "easy".
41 in us alone
No way of knowing- no records of gun ownership.
Impossible to answer. No central data base exists.
As of 2012, there were 51,438 retail gun stores, and 7,356 pawn shops with a gun dealer's license. There are about 62,000 collectors with a Federal Firearms license.