Stacy Winters pleaded guilty to voluntary manslaughter and use of a firearm in relation to a crime of violence in violation of 18 U.S.C. §§ 1112, 1153, 924(c). Under .the United States Sentencing Guidelines, Winters was subject to a maximum sentence of 191 months’ imprisonment. The district court1 ruled that the United States Sentencing Guidelines were not mandatory and sentenced Winters to 240 months’ imprisonment. We affirm.
I. Background
On January 1, 2003, Winters and his brothers were drinking alcohol and driving through Pine Ridge Village, a neighborhood on the Pine Ridge Indian Reservation. Around dusk, Winters encountered Lucien Janis. Winters, known to be affiliated with the TB gang, and Janis, a member of the Ter. Ter. gang, exchanged un-pleasantries. Winters left and went to Louis “Boy” Winters’s home to get a gun.
Boy gave Winters a Colt .45 semi-automatic pistol and a loaded magazine. Winters and his brothers continued to drive around Pine Ridge Village consuming alcohol and eventually drove back to the place where Winters and Janis exchanged words. Winters and one of his brothers confronted Janis. Janis said, “Give me the gun, I’ll shoot myself,” and then Winters shot Janis in the head at close range, killing him instantly. Winters and his brothers then fled the scene back to Boy’s residence. Winters gave Boy the Colt .45 and told him that Winters was in trouble and needed to get out of town. Winters was arrested the following day.
A first indictment charged Winters with second-degree murder and use of a firearm in the commission of a crime. In a superseding information, the second-degree murder charge was replaced with a charge of voluntary manslaughter. Winters pleaded guilty to both charges and the court ordered a presentence investigation report (“PSI”) to be prepared. The PSI noted that while the judges in the District of South Dakota agreed that Blakely v. Washington, 542 U.S. 296, 124 S.Ct. 2531, 159 L.Ed.2d 403 (2004), rendered. the Guidelines unconstitutional, the Guideline computation was being provided for use on an advisory basis.
Under the non-guideline statutory sentence, manslaughter carried a possible ten-year maximum sentence and the firearm charge carried a mandatory ten-year sentence to be served consecutively with the manslaughter. Winters faced a non-guideline statutory maximum of twenty years’ imprisonment (240 months). The PSI indicated that Winters was subject to a range of 41 to 51 months’ imprisonment for the manslaughter2 and a mandatory 120 months for the firearm charge. Accordingly, the PSI recommended a Guideline range for Winters between 161 and 171 months. The district court, however, rejected the recommendation to make a downward adjustment resulting in a Guideline range between 177 and 191 months.
The district court, treating the Guidelines as discretionary, sentenced Winters *858to 240 months’ imprisonment — the statutory maximum. In a statement of reasons, the court stated:
In light of Blakely v. Washington, 542 U.S. 296, 124 S.Ct. 2531, 159 L.Ed.2d 403 (2004), the District Court ruled the Guidelines unconstitutional in this case. Therefore, the Guidelines are not binding on the Court, but they were taken into consideration. The Court also considered the factors set forth in 18 U.S.C. § 3553(a) in imposing the sentence in this case.
Winters objected to the district court holding the United States Sentencing Guidelines unconstitutional and argued that he should be sentenced under the Guidelines. The district court refused. Winters then filed the instant appeal.
Prior to the submission of this case, the United States Supreme Court issued its opinion in United States v. Booker, — U.S. —, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), extending Blakely to the federal guidelines, and, thus, foreclosing Winters’s argument on appeal. Nonetheless, because Booker also mandated that appellate courts review sentences for reasonableness in light of the factors enunciated in 18 U.S.C. § 3553(a), Booker, 125 S.Ct. at 764-66 (Breyer, J.), we requested that Winters submit a supplemental brief addressing the reasonableness of his sentence.
II. Reasonableness
We start by noting that because the district court did not use the Guidelines in a mandatory fashion, Winters did not suffer a Booker-styled Sixth Amendment violation. See Booker, 125 S.Ct. at 750 (Stevens, J.)(explaining that there would be no Sixth Amendment violation “if the guidelines as currently written could be read as merely advisory provisions that recommended, rather than required, the selection of particular sentences in response to differing sets of facts.”). Thus, this case comes to the court in a fashion similar to that of Respondent Fanfan in Booker’s companion case. With respect to Fanfan, the Court stated:
In respondent Fanfan’s case, the District Court held Blakely applicable to the Guidelines. It then imposed a sentence that was authorized by the jury’s verdict — a sentence lower than the sen-" tence authorized by the Guidelines as written. Thus, Fanfan’s sentence does not violate the Sixth Amendment. Nonetheless, the Government (and the defendant should he so choose) may seek resentencing under the system set forth in today’s opinions. Hence we vacate the judgment of the District Court and remand the case for further proceedings consistent with this opinion.
United States v. Booker, — U.S. —, —, 125 S.Ct. 738, 769, 160 L.Ed.2d 621 (2005).
The Court, however, directed appellate courts:
to apply ordinary prudential doctrines, determining, for example, whether the issue was raised below and whether it fails the “plain-error” test [for violations of the Sixth Amendment] ... [and] in cases not involving a Sixth Amendment violation, [to determine] whether resen-tencing is warranted [after] application of the harmless-error doctrine.
Booker, 125 S.Ct. at 769.3 In this case, the district court went through the analytical sentencing-framework prescribed by Booker. Specifically, the district court consulted the Guidelines in an advisory fashion *859and looked to the factors in 18 U.S.C. § 8553(a). Thus, there was no Booker error.
As such, we review Winters’s sentence for reasonableness in light of § 3553(a). See United States v. Killgo, 397 F.3d 628, 630-31 & n. 4 (8th Cir.2005) (explaining that part of Booker’s remedial command requires appellate courts to review the sentence for reasonableness). Accordingly, we must review Winters’s sentence with respect to the following factors:
(1) the nature and circumstances of the offense and the history and characteristics of the defendant;
(2) the need for the sentence imposed—
(A) to reflect the seriousness of the offense, to promote respect for the law, and to provide just punishment for the offense;
(B) to afford adequate deterrence to criminal conduct;
(C) to protect the public from further crimes of the defendant; and
(D) to provide the defendant with needed educational or vocational training, medical care, or other correctional treatment in the most effective manner;
(3) the kinds of sentences available;
(4) the kinds of sentence and the sentencing range established for—
(A) the applicable category of offense committed by the applicable category of defendant as set forth in the guidelines—
(i) issued by the Sentencing Commission pursuant to section 994(a)(1) of title 28, United States Code, subject to any amendments made to such guidelines by act of Congress (regardless of whether such amendments have yet to be incorporated by the Sentencing Commission into amendments issued under section 994(p) of title 28); and
(ii) that, except as provided in section 3742(g), are in effect on the date the defendant is sentenced; or
(B) in the ease of a violation of probation or supervised release, the applicable guidelines or policy statements issued by the Sentencing Commission pursuant to section 994(a)(3) of title 28, United States Code, taking into account any amendments made to such guidelines or policy statements by act of Congress (regardless of whether such amendments have yet to be incorporated by the Sentencing Commission into amendments issued under section 994(p) of title 28);
(5) any pertinent policy statement—
(A) issued by the Sentencing Commission pursuant to section 994(a)(2) of title 28, United States Code, subject to any amendments made to such policy statement by act of Congress (regardless of whether such amendments have yet to be incorporated by the Sentencing Commission into amendments issued under section 994(p) of title 28); and
(B) that, except as provided in section 3742(g), is in effect on the date the defendant is sentenced.
(6) the need to avoid unwarranted sentence disparities among defendants with similar records who have been found guilty of similar conduct; and
(7) the need to provide restitution to any victims of the offense.
18 U.S.C. § 3553(a).4
In his original appeal, Winters argued that the district court erred in *860refusing to grant him an offense-level reduction for acceptance of responsibility. Because § 3353(a)(4), and the mandates of Booker, require courts to consult the Guidelines, an erroneous application of the Guidelines will be but one factor in applying the reasonableness standard. We review a district court’s denial of an acceptance of responsibility adjustment under U.S.S.G. § 3E1.1 for clear error. United States v. Patten, 397 F.3d 1100, 1104-05 (8th Cir.2005). A district court’s factual determination on whether a defendant has demonstrated acceptance of responsibility is entitled to great deference and should be reversed only if it is so clearly erroneous as to be without foundation. United States v. Arellano, 291 F.3d 1032, 1034 (8th Cir.2002).
In the plea agreement, the United States agreed to recommend that Winters demonstrated acceptance of responsibility. In addition, the PSI indicated that Winters satisfied the § 3E1.1 requirements. At the sentencing hearing, the district court explained that “a plea of guilty is not sufficient to trigger the acceptance of responsibility under the guidelines,” and that after examining the file, Winters would not be entitled to an acceptance of responsibility reduction. Indeed “[a] defendant who enters a guilty plea is not entitled to an adjustment under [U.S.S.G. § 3E1.1] as a matter of right.” United States v. Morris, 139 F.3d 582, 584 (8th Cir.1998) (brackets in original)(citing U.S.S.G. § 3E1.1, cmt. n. 3). The district court, which had the opportunity to observe Winters’s demeanor at sentencing, was within its discretion to conclude that he had not accepted responsibility for his offense. See id.
Next we turn to the underlying facts to address the remaining portions of § 3553(a). In this case, Winters, while intoxicated, got into an argument with the victim. He then left the scene and retrieved a gun that he used to shoot the victim at close range in the head. Winters then fled the scene, and tried to dispose of the gun.5 The district court characterized Winters as the “trigger man” and the “hit man.” In addition, the court noted that the crime “was a malicious act which was entirely senseless.”
Although the district court sentenced Winters outside the Guidelines range, we cannot say that the sentence, when viewed in light of the relevant § 3553(a) factors, is unreasonable. The facts offer riothing, other than Winters’s voluntarily *861diminished capacity, to ameliorate the abject brutality of an execution-style slaying of an unarmed person. The district court aptly described it as malicious and senseless. Furthermore, Winters has admitted to being prone to violence. A twenty-year sentence in this case comports with the considerations in § 3553(a)(2) that the sentence reflect the seriousness of the offense, promote respect for the law, provide just punishment for the offense, afford adequate deterrence to criminal conduct, and protects the public from further crimes of the defendant.
Winters relies heavily on the Congressional statement that a Guidelines sentence is necessary to avoid unwarranted sentencing disparities. See 18 U.S.C. § 3353(a)(6). Winters explains that because he received the maximum statutory sentence, his sentence will be quite different from other persons with no criminal history who commit voluntary manslaughter. However, each case must be judged on its own facts and few cases will present facts like this one. Applying Winters’s argument, that the range of reasonableness is essentially co-extensive with the Guidelines range, would effectively render the. Guidelines mandatory. We have been directed to review a sentence for reasonableness based on all the factors listed in § 3353(a)(6). The Guidelines range is merely one factor. We cannot isolate possible sentencing disparity to the exclusion of the all the other § 3553(a) factors.
For the foregoing reasons, we conclude that Winters’s sentence is reasonable and affirm.
. The Honorable Richard H. Battey, United States District Judge for the District of South Dakota.
. The PSI gave Winters a three-level downward adjustment for acceptance of responsibility, otherwise, he would have been subject to a range of between 57 and 71 months’ imprisonment for voluntary manslaughter.
. The Court, however, did not apply either the plain-error test or harmless-error test to Booker or Fanfan. Presumably, the Court vacated Fanfan’s sentence and remanded the case so that the district court would have the guidance of Booker in calculating Fanfan’s sentence.
. While we are to judge the sentence for reasonableness, district courts are to impose a reasonable sentence. In crafting the reasonableness standard of review for appellate courts, the Supreme Court noted that appel*860late courts are familiar with the standard as the Federal Sentencing Act has "long required [its] use in important sentencing circumstances — both on review of departures ... and on review of sentences imposed where there was no applicable Guideline.” Booker, 125 S.Ct. at 766. Previously, our reasonableness standard for departures was judged in three parts:
First, as a question of law, the court determines whether the circumstances on which the district court relied for departure are sufficiently unusual in kind or degree to warrant departure. Second, as a question of fact, the court determines whether the circumstances justifying departure actually exist. Third, with deference to the district court, the court reviews the reasonableness of the degree of departure under an abuse of discretion standard.
United States v. Joshua, 40 F.3d 948, 951 (8th Cir.1994) (citing United States v. Sweet, 985 F.2d 443, 445 (8th Cir.1993)). With respect to the third factor, we have explained that it is the district court, not us, that makes this judgment call of reasonableness. United States v. Sweet, 985 F.2d 443, 445 n. 2 (8th Cir.1993). Accordingly, we must give "due regard to the district court's superior feel for the case.” Id. (internal quotations omitted).
. Winters returned the gun to Boy, who, in turn, gave it to his wife with instructions to pass it on to a third person, Leon Janis, and get rid of it. Leon gave the gun to a fourth person who subsequently notified the authorities and allowed them to recover the weapon.