Yunus, I lived in the People's Republic of Maryland before I retired from the Army, just do what I did, move to Texas. Got my Cancealed Handgun License (CHL) and that means no NICS check when buying a gun of any type and no license even needed to carry cancealed in my car. Big difference, even my wife who was born in Baltimore doesn;t miss the People's Republic.
I cannot speak for any of the states with additional laws; but this applies in Texas and Colorado and most other "normal" states.
I have an FFL....
I can sell a handgun or longgun to any resident of Colorado...who (obviously) passes the background check.
I can sell a longgun to a resident of any state as long as possession of the gun in his home state is legal.
All gun transfers must take place at my licensed premises...except for bonafide gun shows in Colorado. I can set up and display and take orders at gun shows in other states; but I must come back to Colorado and ship any guns sold to an FFL in the Buyer's area.
I cannot sell a handgun to a resident of another state. Yes, I can (and have) sell handguns by shipping it to an FFL in the buyer's area. This is standard procedure with Internet sales.
After a firearm has been in my personal log book for 12 months, I can sell it like any other individual to any resident of Colorado. I can even ship it to a buyer's home as long as I don't use the USPS for handgun shipment. Longguns can be shipped by USPS.