Thoughts from case law:
"[T]he proof showed conclusively that appellant had no license, purchased thirty guns from dealers in El Paso during a four month period and sold them for a profit in this country and Mexico. This evidence amply satisfied the definition of dealing in firearms."
United States v. Hernandez, 662 F.2d 289, 291 (5th Cir. 1981)
"[T]he government must prove both willingness to deal and more than an occasional sale in order to prove the status of the accused as one engaged in the business of dealing in firearms."
"[T]he test...for determining whether an accused is engaged in the business of dealing in firearms is whether he has guns on hand or is ready and able to procure them for the purpose of selling them from time to time to such persons as might be accepted as customers."
United States v. Berry, 644 F.2d 1034, 1037 (5th Cir. 1981)
"[T]he Government need not prove that the defendant's primary business was dealing in firearms or that he necessarily made a profit from such dealing; 'it must (however) show a willingness (on the defendant's part) to deal, a profit motive, and a greater degree of activity than occasional sales by a hobbyist.'"
United States v. Masters, 622 F.2d 83, 88 (4th Cir. 1980)
"While we can conceive of a single transaction sufficiently large enough in number of guns and the price paid to constitute engaging in the business of dealing in firearms, ordinarily one sale will not be sufficient to meet the statutory requirement. The use of the word “dealing” connotes a regular course of conduct carried on over a period of time or, at least, on more than one or two unrelated occasions."
United States v. Tarr, 589 F.2d 55, 59 (1st Cir. 1978)
"[T]he proof showed conclusively that appellant had no license, purchased thirty guns from dealers in El Paso during a four month period and sold them for a profit in this country and Mexico. This evidence amply satisfied the definition of dealing in firearms."
United States v. Hernandez, 662 F.2d 289, 291 (5th Cir. 1981)
"[T]he government must prove both willingness to deal and more than an occasional sale in order to prove the status of the accused as one engaged in the business of dealing in firearms."
"[T]he test...for determining whether an accused is engaged in the business of dealing in firearms is whether he has guns on hand or is ready and able to procure them for the purpose of selling them from time to time to such persons as might be accepted as customers."
United States v. Berry, 644 F.2d 1034, 1037 (5th Cir. 1981)
"[T]he Government need not prove that the defendant's primary business was dealing in firearms or that he necessarily made a profit from such dealing; 'it must (however) show a willingness (on the defendant's part) to deal, a profit motive, and a greater degree of activity than occasional sales by a hobbyist.'"
United States v. Masters, 622 F.2d 83, 88 (4th Cir. 1980)
"While we can conceive of a single transaction sufficiently large enough in number of guns and the price paid to constitute engaging in the business of dealing in firearms, ordinarily one sale will not be sufficient to meet the statutory requirement. The use of the word “dealing” connotes a regular course of conduct carried on over a period of time or, at least, on more than one or two unrelated occasions."
United States v. Tarr, 589 F.2d 55, 59 (1st Cir. 1978)