Americans own more guns than the people of any other nation. Even after taking into account a margin for error, the US is unambiguously and without question at the top of the list. In 2007, the Small Arms Survey project found that the number of Americans that owned guns was equal to 88.8 per 100. International hotspot Yemen came in second with 54.8 Neutral nation Switzerland was third with 45.7. Russian neighbor Finland was fourth with 45.3. Balkan nation Serbia rounded out the top 5 with 37.8. In 2009, the Congressional Research Service (PDF warning) estimated that there were 310 million guns in private hands. The US Census Bureau estimated there were 281,421,906 Americans. That means there were more guns than people. It comes out to being 110.2 guns for every 100 Americans.
As we've discussed before, not all criminal records are equal. Federal law - 18 USC 922 in particular - bans people who have been convicted of felonies and misdemeanor domestic violence from possessing a gun. (As an aside, if a person is subject to a domestic violence restraining order, they are also prohibited from possessing a firearm.) Every state has laws that overlap, changing some of the rules. For example, California Penal Code Sections 29800-29830, a person convicted of misdemeanor domestic violence may qualify to have their gun possession rights restored after 10 years.
Regardless of the laws of your state, 18 USC 921 makes it clear which misdemeanors qualify as domestic violence. For a misdemeanor to qualify as a domestic violence misdemeanor that bars you from possessing a firearm, it must meet two tests. First, it must involve physical force, an attempt to use physical force, or a threat to use a deadly weapon. Second, the defendant must generally be either the victim's current or former spouse, parent, or guardian, share a child with the victim, live with or have lived with the victim as a spouse, parent, or guardian, or be similar to a spouse, parent, or guardian of the victim.
In 2009, the Supreme Court made a ruling related to what a domestic violence misdemeanor means. Their ruling in United States v. Hayes, 555 U.S. 415 (2009) (PDF warning) stated that a misdemeanor doesn't need to be labeled as a "domestic violence" crime in the statute's language to qualify for the federal prohibition of gun ownership. It only had to meet the test established by federal legislation.
In March of 2014, the United States Supreme Court cleared up what the federal legislation defines as force under the domestic violence prohibition. In United States v. Castleman, 572 U.S. 134 (2014) (PDF warning), the Supreme Court ruled that "force" means more than just violent force – it also includes offensive touching. Furthermore, if a relationship actually exists, the requirements of state or local domestic violence rules did not matter. This expanded rule meant crimes like battery, which don't necessarily involve violence, would qualify under this ban.
The reasoning for the Court's ruling in this case was because the assaults committed by people in intimate relationships was usually something relatively minor, such as pushing, grabbing, or slapping. In fact, even an unsuccessful attempt at such an act would qualify as a domestic violence misdemeanor, barring the defendant from possessing a firearm under federal law.
Federal law does provide for protection to those who have had their criminal record expunged, set aside, pardoned, or had their civil rights restored. Federal law also permits the government to have a process that allows for a person to seek an exemption from the federal prohibition. Depending on the state and a person's criminal record, an equivalent process exists for gun ownership rights on a state level. Thankfully, it is relatively easy to find out if your state allows you to re-establish your right to gun ownership.