Sorry I've been away for a few days, gents, but appreciate the replies. The C&R is a form of FFL that allows firearms 50+ years old (that don't have other restrictions) to be shipped to you directly. It involves an application, fees, and background check with ATF.
This is correct. That said, a lot of pre-1972 sporting firearms are now C&R by definition. I picked up a Winchester Model 50 made in 1957 and used my C&R FFL to have it delivered to me.Topping off and C&R FFLs. Be very careful with the rules. A lot of people think “oh, an old Swedish mauser is a C&R, therefore I can buy this gun on my C&R license”. Maybe. A “sporter” is not a curio. It is no longer original. That is a violation of the license. The only way a sporter is a curio and relic is if the work done to make the custom rifle is absolutely provable to have occurred 50+ years ago. (Prior to 1972 as of today’s writing).
So a Swedish Mauser in military condition is a C&R. A custom Swede customized in 1950 by Griffin & Howe is a C&R. But an online auction for an unknown age customized Swede is a modern rifle. Don’t cross the BATF!