You can find the info. on the BATFE website. There are several types of FFLs, from Curio and Relic, to full blown manufacturing. IIRC, you have to have an actual store front for the standard FFL, as well as show some type of transactions during the year. It depends on what you want to do with the license. I think quite a few guys have a C&R to purchase older firearms, and get discounts from places like Brownells.