Can I ship a BB gun across state lines? Alcohol?

So I live in NC, my sister and my bro-in-law live in TN. They are both lawyers but I can't ask them this question because it'll give away their christmas gifts. I got him a novelty bottle of vodka, and I got her a pink BB gun. He likes drinking, and she likes pink and has always wanted a BB gun (even though they are in their late 30s). What is the legality of shipping these across state lines? Is there a specific carrier I need to use, or something that I need to note on the side of the box and at the depot? Thanks!