
    UNITED STATES of America, Appellee, v. Charles David JOHNSON, Appellant.
    No. 03-2665.
    United States Court of Appeals, Eighth Circuit.
    Submitted Feb. 6, 2004.
    Decided Feb. 27, 2004.
    
      Angela S. Jegley, Little Rock, AR, for Plaintiff-Appellee.
    Charles David Johnson, Forrest City, AR, John Wesley Hall, Jr., John Wesley Hall, Jr., P.C., Little Rock, AR, for Defendant-Appellant.
    Before MELLOY, HANSEN, and COLLOTON, Circuit Judges.
   PER CURIAM.

Charles Johnson appeals the sentence the district court imposed after he pleaded guilty to a drug charge. Following our review of counsel’s brief filed under Anders v. California, 386 U.S. 738, 87 S.Ct. 1396, 18 L.Ed.2d 493 (1967), as well as Johnson’s pro se supplemental brief, we conclude that Johnson cannot challenge an offense-level enhancement for possession of a dangerous weapon after stipulating to such an enhancement in the plea agreement, see United States v. Nguyen, 46 F.3d 781, 783 (8th Cir.1995), and that his ineffective-assistance arguments would be more properly raised in a collateral proceeding, see United States v. Cain, 134 F.3d 1345, 1352 (8th Cir.1998). In addition, we have reviewed the record independently for nonfrivolous issues under Penson v. Ohio, 488 U.S. 75, 109 S.Ct. 346, 102 L.Ed.2d 300 (1988), and we find none.

Accordingly, we affirm. Counsel’s motion to withdraw is granted. 
      
      . The Honorable George Howard, Jr., United States District Judge for the Eastern District of Arkansas.
     