In this case, defendant challenges his conviction on separate counts of distributing cocaine, possession of a firearm in furtherance of a drug-trafficking crime, and possession of a sawed-off shotgun, on grounds that the evidence was insufficient to convict him of possession of a firearm in furtherance of a drug-trafficking crime. He also challenges the application of several sentence enhancements. Judgment is affirmed, where: 1) substantial evidence supported the jury's conclusion that defendant considered the firearm to be critical to his drug-trafficking activities; 2) enhancing a defendant's offense level based on the number of weapons involved in the offense underlying his 18 U.S.C. section 924(c) conviction does not constitute impermissible double counting; and 3) the four-level enhancement was properly imposed under U.S.S.G. section 2K2.1(b)(5) on grounds that defendant "engaged in the trafficking of firearms."