
    UNITED STATES of America v. Eric WILLIS, Appellant.
    No. 11-3582.
    United States Court of Appeals, Third Circuit.
    Submitted for Possible Summary Action Pursuant to Third Circuit LAR 27.4 and I.O.P. 10.6 Nov. 17, 2011.
    Opinion filed: March 14, 2012.
    Salvatore L. Astolfi, Esq., Office of United States Attorney, Philadelphia, PA, for Appellee.
    Eric Willis, Loretto, PA, pro se.
    Before: RENDELL, HARDIMAN and ROTH, Circuit Judges.
   OPINION OF THE COURT

PER CURIAM.

As we write primarily for the parties, we will recite only the facts pertinent to this appeal. In 2004, defendant-appellant Eric Willis (‘Willis”) pleaded guilty to several charges stemming from a 2003 robbery of a U-Haul store in Philadelphia. His sentence included a consecutive ten-year term of incarceration — a mandatory minimum imposed by 18 U.S.C. § 924(c)(l)(B)(i)— derived from a coconspirator’s possession of a shotgun during the robbery. Willis has unsuccessfully challenged his sentence on both direct and collateral review. See generally United States v. Willis, C.A. No. 10-3585 (3d Cir., order entered Dec. 6, 2010); United States v. Willis, 186 Fed.Appx. 198 (3d Cir.2006).

In June of 2011, Willis commenced a new attack on his sentence, filing a motion pursuant to 18 U.S.C. § 8582(c)(2). He claimed that “Amendment 599” had lowered his Guideline range, thereby justifying relief under § 3582. The District Court disagreed and denied the motion, observing that the relevant “sentencing guideline range [was] unaffected” by Amendment 599. Willis filed a timely notice of appeal.

We have jurisdiction under 28 U.S.C. § 1291. While we review the District Court’s order primarily for abuse of discretion, our review of legal questions is plenary. See United States v. Mateo, 560 F.3d 152, 154 & n. 2 (3d Cir.2009).

We agree with the Government that Willis cannot obtain relief under § 3582(c). Even if Amendment 599, which antedated Willis’s sentencing by several years, applied in the fashion he claims, it is clear from the pre-sentence report that Willis never received a firearms enhancement; rather, the lengthy sentence imposed by the District Court derived, in part, from the mandatory minimum required by 18 U.S.C. § 924(c)(l)(B)(i). A mandatory-minimum term of imprisonment required by statute is not an element of the Guidelines, and Willis therefore cannot challenge that portion of his sentence via § 3582. See Dillon v. United States, — U.S.-, 130 S.Ct. 2683, 2691, 177 L.Ed.2d 271 (2010) (“[Section 3582(c)(2) ] applies only to a limited class of prisoners — namely, those whose sentence was based on a sentencing range subsequently lowered by the Commission.”). Rather, a motion under 28 U.S.C. § 2255 is the proper mechanism for challenging a federal conviction or sentence. See In re Dorsainvil, 119 F.3d 245, 249 (3d Cir.1997); see also United States v. Carter, 500 F.3d 486, 490 (6th Cir.2007) (distinguishing between motions brought under § 3582(c) and those brought under § 2255).

“Because this appeal does not present a substantial question, we will summarily affirm the District Court’s judgment.” Murray v. Bledsoe, 650 F.3d 246, 248 (3d Cir.2011); see also 3d Cir. L.A.R. 27.4; I.O.P. 10.6. 
      
      . Amendment 599 expanded the commentary to U.S.S.G. § 2K2.4 on the use of a firearm during or in relation to certain crimes, and clarified under what circumstances defendants sentenced for violations of 18 U.S.C. § 924(c) in conjunction with convictions for other offenses may receive weapon enhancements contained in the Guidelines for those other offenses. See 3 U.S. Sentencing Comm’n, Guidelines Manual C-572-74 (2010), available at http://www.ussc.gov/ Guidelines/201 l_Guidelines/ManuaL PDF/Appendix_C_Vol_II.pdf (2011 edition with identical textual content). Amendment 599 went into effect on November 1, 2000, and was made retroactive pursuant to U.S.S.G. § IB 1.10. For a discussion of Amendment 599, see United States v. Goines, 357 F.3d 469 (4th Cir.2004).
     