Nonsense. There is no limit on the number of firearms a person can sell per year/month/day. The violation of Federal law occurs when you engage in the business of dealing in firearms without a license. ATF defines engaging in the business as the repetitive buying and selling of firearms for profit. If you have 1,000 guns in your collection you can legally sell them all on the same day without need for an FFL. If you buy one gun today with the intent to resell it for profit tomorrow......you may be engaging in the business and better have an FFL.