18 USC 2231 - Assault or resistance

(a) Whoever forcibly assaults, resists, opposes, prevents, impedes, intimidates, or interferes with any person authorized to serve or execute search warrants or to make searches and seizures while engaged in the performance of his duties with regard thereto or on account of the performance of such duties, shall be fined under this title or imprisoned not more than three years, or both; and
(b) Whoever, in committing any act in violation of this section, uses any deadly or dangerous weapon, shall be fined under this title or imprisoned not more than ten years, or both.