SCOTUS review of 18 USC 924(c)(1)
18 US Code §924(c)(1)(A) provides for an additional, consecutive, five year mandatory minimum if the defendant "uses or carries a firearm" in "any crime of violence or drug trafficking crime." (The punishment escalates if the defendant actually brandishes or fires it).
I just received an amicus brief from Gun Owners' Foundation, in the pending Supreme Court case of Watson v. United States. (Order granting cert. here. It appears that Watson was the recipient of the firearm in the exchange; he talked to an informant about buying a gun, and the informant helpfully suggested that he knew someone willing to sell one in exchange for drugs. The core question is whether a defendant who swaps drugs for a gun has "used" the gun in a drug trafficing crime, and the amicus argues that using it as payment is not "using" it within the meaning of the statute. It notes that the Circuits have split 2-2 on the issue.