Wear and tear would eventually be a problem. Usually the people that own these unregistered firearms maintain them sufficiently.

Often they also have multiple firearms of the same or similar type.

A good example is the SKS rifle. I suppose the US was similar to Australia. In the 1970s to the early 1990s in Australia, the SKS was a cheap,value for money firearm. Especially the Chinese Norinco manufactured SKS. These firearms flooded into the country.

When New South Wales and Victoria banned semi automatic firearms in 1986, people in the other States bought semi automatic firearms in large numbers, especially the SKS rifles (excellent for wild pigs ect)

Approximately 350,000 SKS rifles were sold in Queensland. The numbers sold in the other States was really unknown because records weren't necessary.

With the Federal Government firearm buy back in 1996, they only got 290,000 SKS rifles handed in across the entire Nation!

The number of other types semi automatics is completely unknown.

Firearm control and bans don't really work. The Authorities don't have the manpower or money to try to track suspected firearm offenders.

Wear and tear would eventually be a problem. Usually the people that own these unregistered firearms maintain them sufficiently.

Often they also have multiple firearms of the same or similar type.

A good example is the SKS rifle. I suppose the US was similar to Australia. In the 1970s to the early 1990s in Australia, the SKS was a cheap,value for money firearm. Especially the Chinese Norinco manufactured SKS. These firearms flooded into the country.

When New South Wales and Victoria banned semi automatic firearms in 1986, people in the other States bought semi automatic firearms in large numbers, especially the SKS rifles (excellent for wild pigs ect)

Approximately 350,000 SKS rifles were sold in Queensland. The numbers sold in the other States was really unknown because records weren't necessary.

With the Federal Government firearm buy back in 1996, they only got 290,000 SKS rifles handed in across the entire Nation!

The number of other semi automatics is completely unknown.

Firearm control and bans don't really work. The Authorities don't have the manpower or money to try to track suspected firearm offenders.