The right of Americans to have a gun is guaranteed by the Second Amendment to the US Constitution. Under current federal regulations, firearms may not be sold to people who have mental health problems, previously convicted of crimes (here fall as well people suspected of violating the law, who are brought to justice for domestic violence and so on.), drug addicts and non-citizens of the United States (here are some exceptions, but not many). Pistols usually can be purchased only by people over 21, guns – upon reaching 18 years of age. When buying weapons in the store the buyer fills in a special questionnaire, where he enters his home address, place of work and so on., Signs a number of documents (and thus declares that all given information is accurate), and, in some states, leaves the imprint of their right thumb. The buyer is also required to show his ID to the seller, in some states to buy weapons it is necessary to pass a special course.
By the way, I highly recommend Concealed Carry & Home Defense Crash Course. This course is one of the best ones! In the 46 US states there are no restrictions on the purchase of the number of trunks. Only in four states, there’s a rule according to which the buyer can purchase one gun (pistol, rifle, etc.) per month. In 43 states, the acquisition of weapons does not require a license or registration. In 44 states in any way regulated market secondary weapons (ie, gun owner is free to sell it to anyone who wishes). In 27 states the customer is checked not only at the federal data base of criminals, but also in the state databases (respectively, in 23 states such a request is sent only to the federal government). 40 states prohibit counties and individual municipalities to pass laws, toughening or softening the existing rules of this kind. Becoming the owner of the weapon needs to check additional materials on the proper use of it.