I can tell you, selling name brand firearms, is a good way to make no money whatsoever. Since you got your 07, you can do fairly well building to spec for customers. If you have a lot of land, you can build a few machine guns and rent them to let people get the pray and spray experience. You can make a little money on ammunition, and accessories as well. Probably 90% or better of everything I have made since I have had mine has been selling service though. Repairs and cleaning can be a good money maker, and since you're new, I would definitely do as many transfers as I could stand, so you can get your name in front of customers. Transfers are basically free money, and they will get you a shot at a targeted audience. Only downside to transfers, is there are plenty of those guys that don't even want to unass the 25 bones for you to do that. For some reason a lot of folks feel like it is a negotiable thing. "You, know, since I spent all this money on this gun, you should give me a break on the transfer fee." Makes me want to punch em in the throat. lol
I have been an FFL for 12 years now. Shoot me a PM if you have any questions man.