concurring:
I concur with the majority with respect to its disposition that there was no plain error in the district court’s description of the essential elements of an offense under 18 U.S.C. § 924(c)(1). I also agree with the majority that there was no plain error in the district court’s reliance on testimony from another trial in concluding that Knobloeh was a leader, organizer, or supervisor. I, therefore, join with it as to these aspects of its opinion. I write. separately primarily because, although I agree with the result the majority reaches as-to all three issues in this appeal, I cannot agree that plain error is the proper standard of review of the defendant’s claim that the district court improperly enhanced his base offense level based on his possession of two firearms in connection'with his storing a cache of steroids in his apartment.
As to the weapons possession issue, Knob-loch contends that the enhancement violated U.S.S.G. § 2K2.4, Application Note 2. See Maj. op. at 371 (quoting Application Note 2). According to Knobloeh, the application note prohibits .a district court from enhancing, pursuant to U.S.S.G. § 2D1.1(b)(1), a defendant’s base offense level for possessing a firearm when the defendant also is to be sentenced for a violation of 18 U.S.C. § 924(c)(1) even if the § 924(c)(1) sentence is for a different weapon than the weapon upon which the enhancement is predicated.
The majority and I agree that Knobloeh is correct on this point. The majority, however, concludes that plain error is the standard of review of this claim. See Maj. op. at 367, 370. The plain error standard of review applies on appeal when a defendant fails to object to an error in the court' below. See Fed.R.Crim.P. 62(b). The record and thg briefs do not support the majority’s conclusion that Knobloeh failed to object to the enhancement. The Government explicitly and unequivocally conceded in its brief that Knobloeh properly preserved this issue for appeal. Indeed, it stated that Knobloch’s challenge “presents a legal issue subject to plenary review,” see Gov’t’s br. at 2, and the Government never even mentioned “plain error” in connection with its argument on this issue. Id. at 23-25. That concession was appropriate in light of Knobloch’s timely objection to the imposition of the enhancement, *374albeit on a slightly different ground, (see App. at 80-81); and the probation officer’s refusal to recommend the enhancement citing Application Note 2. See Addendum to Presentence Investigation Report at 1. I do not think that this court should second guess the Government’s concession in its brief that Knobloch properly preserved this issue for appeal especially when there is no reason to do so.
Although this may appear to be a small point, it is critical to this case. If plain error is the appropriate standard of review of Knobloch’s claim, this court could not correct the error. A court of appeals may correct an unobjected-to error only if the error was “plain” and if it affected the defendant’s “substantial rights.” Fed.R.Crim.P. 52(b); United States v. Olano, 507 U.S. 725, 732, 113 S.Ct. 1770, 1776, 123 L.Ed.2d 508 (1993). An error is plain only if it is “clear” or “obvious.” 507 U.S. at 734, 113 S.Ct. at 1777 (citing United States v. Young, 470 U.S. 1, 17 n. 14, 105 S.Ct. 1038, 1047 n. 14, 84 L.Ed.2d 1 (1985) and United States v. Frady, 456 U.S. 152, 163, 102 S.Ct. 1584, 1592, 71 L.Ed.2d 816 (1982)). The rules permit a court of appeals' to correct such an error because it is so clear or obvious that the district court should have avoided it even if it was not pointed out by the parties. The error committed .by the district court in this case certainly was not clear or obvious. Indeed, the district court’s construction of Application Note 2 may have been, flawed but it was reasonable, was supported by case law from three other courts of appeal, and there are no cases to the contrary. The Fifth, Ninth, and Eleventh Circuit courts of appeal have all addressed this issue and determined that enhancement of a defendant’s base offense level based on the possession of a firearm is permitted even when a defendant will receive a § 924(c)(1) sentence as long as the enhancement and sentence are based on different weapons, as is the case here. See United States v. Willett, 90 F.3d 404, 408 (9th Cir.1996) (“We find that the district court did not err in imposing the two-level enhancement on top of the § 924(c) conviction because the commission of a drug trafficking crime with a gun, silencer and knife poses a greater risk than does the commission of the same crime with only a gun”); United States v. Washington, 44 F.3d 1271, 1280-81 (5th Cir.1995) (permitting two-level enhancement based on co-conspirator’s handgun possession when defendant is also to receive § 924(c) sentence for a different weapon); United States v. Kimmons, 965 F.2d 1001, 1011 (11th Cir.1992) (same). Even if those cases are distinguishable on the grounds offered by the majority, they are not so plainly or obviously so as to make reliance upon them unreasonable. I, therefore, believe that under these circumstances, plain eiTor should not be ascribed to the district court and the defendant may unequivocally raise the issue on appeal.
I also note my disagreement with the majority’s statement that the sentencing guidelines “authorize[ ] a specific offense characteristic enhancement only for a dangerous weapon possessed in connection with the offense of conviction_” Maj. op. at 372. Although philosophically I may agree that this should be the rule, the language of the guidelines and the case law are to the contrary. It is well settled that when sentencing a defendant, a district court must consider all conduct relevant to the offense of conviction. U.S.S.G. § 1B1.3 provides that specific offense characteristics applied in controlled substance possession and distribution cases are to be determined based on “all acts and omissions ... that were part of the same course of conduct or common scheme or plan as the offense of conviction.” See also United States v. Frierson, 945 F.2d 650, 652-53 (3d Cir.1991) (“relevant conduct also includes all acts and omissions that were ‘part of the same course of conduct or common scheme or plan as the offense of conviction’ ”) (quoting U.S.S.G. § 1B1.3).1 According to the guideline commentary, offenses are part of the same course of conduct if they are similar to each other or are committed close in time. See U.S.S.G. § IB 1.3, Application Note 9(B).
*375In this case, there is no serious dispute that Knobloeh’s August 28, 1995, possession of the steroids in his apartment is part of the same course of conduct as the offense of conviction, the August 28, 1995, distribution of steroids to Davis. Both offenses were committed on the same day and involve the same drug. If that is the case, then the possession of the two firearms in connection with the steroids stored in Knobloch’s apartment must be part of the same course of conduct as the distribution of steroids to Davis. Thus, application of the specific offense characteristic of firearms possession is appropriate. U.S.S.G. § 1B1.3, Application Note 3 does not support the majority’s conclusion that specific offense characteristics only apply to the offense of conviction. Indeed, that application note states that conduct for which the defendant was not convicted must be considered in calculating an offense level as long as it comes within the definition of § 1B1.3.
Nonetheless, I would still reverse the district court on this issue because U.S.S.G. § 2K2.4, Application Note 2 prohibits a district court from enhancing a defendants’ Offense level no matter how many weapons a defendant possesses if he is to receive a sentence for a § 924(c)(1) violation as long as all of the weapons are possessed or used as part of the same course of conduct or common plan or scheme. This conclusion is mandated by the broad language used by the guideline drafters. Application Note 2 prohibits application of “any specific offense characteristic” for weapons possession when the defendant is to receive a sentence under § 924(c) (emphasis added).
. Accord United States v. Ortega, 94 F.3d 764, 767-68 (2d Cir.1996); United States v. Ignancio Munio, 909 F.2d 436, 439 (11th Cir.1990).