This is US Federal Law, your individual State may have stronger restrictions but no states can have 'fewer' restrictions.
To purchase a hand gun from a FFL (Federal Firearms Licensee) you have to be 21 years old.
To purchase a hand gun in a FTF (Face to Face) you have to be 18.
To possess or use a hand gun and be under the age of 18 you have to be in the 'immediate' presence of a legal guardian. If not the weapons have to be secured either in a safe or unloaded and trigger locked.
Rifles/Shotguns maybe purchased by ages 18 and up from a FFL.
Pistol ammunition can not be purchased by anyone under the age of 21 legally.
The exception, there are .22 cal, .45 cal and 9mm rifles that exist, so someone under the age of 21 may purchase ammunition legally if they tell the clerk it's for a rifle. (I don't understand this law either.)
Everyone who purchases a firearm from a FFL must submit to the NICS check. (National Instant Background Check System) Every single time a firearm is purchased you have to submit to this.
There is no federal waiting period, however most states have them.
In a 'face to face' transaction you can legally sell to anyone, criminal or otherwise, but...... When getting the NICS check done the serial number of your weapon is submitted to the FBI and BATFE, if you sell a FFL purchased weapon in a face to face and that person committs a crime with the gun you sold you're getting the first visit from the police. You had better make sure you got a receipt for the sale and it's good to have a photo copy of the persons ID and hang on to it for life.
I personally won't sell a gun to anyone I don't know. I also require that they have a Concealed Weapons Permit and a State ID, and be willing to sign a 'transfere' receipt. That way if that gun gets stolen from them and used in a crime or if they use it in a crime I have ample evidence that the firearm is no longer mine.
THe 'face to face' transaction is the so called 'gun show loophole.' The 'liberal' feds are trying to prevent face to face transactions. This really won't effect most gun shows since most of them are run by FFL dealers. However there are 'panderers' at the shows trying to buy and sell guns who aren't FFL's. If someone makes a career or profit of FTF sales, they are committing a crime, after a certain ammount you can become an illegal arms dealer if you don't have a FFL. There are quite a few people who have gotten caught in this 'gray' area of selling guns, the ATF takes it very seriously.
To close this loophole would criminalize CnR sellers who not currently required to posess a FFL. CnR means Curious and Relics, or 'older than shit' guns. CnR's are generally non functioning or antique weapons, many no longer have ammunition made for them, basically collectables. To illegalize FTF transfers would completely stop collectors from obtaining or selling thier pieces because many of their sales are done via association or internet advertisements. If they have to open shop or have a FFL booth at a gun show the sales are so slow and individual that they wouldn't make any money, it's a VERY limited market.
The ONLY gun I ever sold also involved a NICS check that I required. I paid a FFL to run the NICS check on the guy I was selling to. I knew him and we both agreed that it was best to keep it more than 100% above the level.
Hopefully that answers some questions about buying and selling arms.
There's no Federal registration required, there's no federal licesnse. Many states require such things .. the free ones do not.
-RT76
