Originally Posted by mjes92
Any words of caution when mailing a non-restricted rifle to a FFL?
Yes; other than what Aguila and Armorer already stated, be aware that the postal definition of a "short-barreled rifle" and/or "firearm... capable of being concealed on the person" is subtly different from the NFA definition and other familiar federal definitions in an important way.
The postal regs define a "short-barreled rifle" as...
...any weapon made from a rifle (by alteration or modification) resulting in an overall length of less than 26 inches.
IOW the rifle must be at least 26" long as mailed
. Do NOT disassemble it to fit into a smaller package; your attempt to save on shipping costs could land you in hot water!
This is particularly important with modular firearms such as AR's.