A jury convicted Anthony Wilson Kings-berry of five drug and firearm offenses. Kingsberry was sentenced as a career offender and received three concurrent terms of life imprisonment, a concurrent two hundred and forty month sentence and a mandatory consecutive sixty month sentence. Kingsberry filed a motion pursuant to 28 U.S.C. § 2255 (Supp. Ill 1997) to vacate, set aside or correct his sentence. Kingsberry argues that his trial counsel was ineffective regarding an alleged plea offer by advising him inaccurately as to his sentencing exposure and potential classification as a career offender. The district court1 denied relief without an evidentiary hearing. Kingsberry appeals, and we affirm.
I. BACKGROUND
This appeal revolves around an alleged plea agreement offer, the substance and, indeed, existence of which is disputed. The parties agree that prior to trial, in an effort to initiate plea agreement negotiations, Kingsberry made a proffer of information regarding related criminal activity. The government accepted the proffer and undertook investigation.
The district court received contradictory affidavits regarding the success of this proffer.2 Kingsberry alleges that a plea agreement offer was subsequently made and communicated to him by his trial counsel, Mr. Price. Kingsberry submitted his own affidavit, as well as the affidavit of his wife, Tara Kingsberry, as evidence of the plea agreement offer and its terms. See Appellant’s Ex.App. at 13-15. Conversely, the government contends that upon conducting the proffer it determined that Kingsberry was being uncooperative and untruthful. As such, the government claims that a formal plea agreement offer never materialized.3 The government submitted the affidavit of Kingsberry’s trial counsel, Mr. S. Dean Price, to corroborate its version of the events. See Appellee’s Ex.App. at 16-20.
In any event, Kingsberry proceeded to trial and was convicted. Because the instant offenses involved a controlled substance and he had been convicted previously of three separate violent felonies, Kingsberry’s Presentence Investigation Report recommended that he be sentenced as a career offender pursuant to § 4B1.1 *1032of the Sentencing Guidelines. At the sentencing hearing, Mr. Price asserted that Kingsberry did not qualify as a career offender. He opined that because the three previous offenses had been consolidated for sentencing they were “related” and therefore, considered appropriately as only one offense under Application Note 3 to § 4A1.2.4 The district court rejected this argument, finding that the offenses occurred on three different dates and resulted in two separate arrests, thereby constituting an “intervening arrest” under that same application note. As a result, Kings-berry fell within the purview of § 4B1.1 and was sentenced as a career offender.
II. DISCUSSION
Kingsberry seeks post-conviction relief, claiming that his trial counsel was constitutionally ineffective during the plea process. Kingsberry contends that Mr. Price misunderstood the term “intervening arrest” and concomitantly the career; offender requirements as they applied to him. Consequently, Kingsberry alleges, he was not advised -of his potential status as a career offender and, perceiving only a minor variance in, potential sentencing exposure, he proceeded erroneously to trial. He argues that the district court erred in denying him an evidentiary hearing. We review the district court’s denial of an evidentiary hearing for an abuse of discretion. See Widgery v. United States, 796 F.2d 223, 224 (8th Cir.1986).
An evidentiary hearing on a § 2255 motion must be granted unless the motion, files and records of the case establish conclusively that the petitioner is not entitled to ' relief. See 28 U.S.C. § 2255. (Supp. Ill 1997); Voytik v. United States, 778 F.2d 1306, 1308 (8th Cir.1985). To obtain relief for ineffective assistance of trial counsel under Strickland v. Washington, 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), a petitioner must show that “counsel’s representation fell below an objective standard of reasonableness” and that this “deficient performance prejudiced the defense.” Id. at 687-88, 104 S.Ct. 2052. If the petitioner makes an insufficient showing on one component, the court need not address both components. See id. at 697, 104 S.Ct. 2052.
We address the prejudice component, assuming arguendo that the performance of Kingsberry’s trial counsel fell below an objective standard of reasonableness. We begin by noting that prejudice is possible, notwithstanding a subsequent fair trial, where counsel failed to provide accurate advice regarding a plea agreement offer. See Engelen v. United States, 68 F.3d 238, 241 (8th Cir.1995) (citation omitted). See also United States v. Rodriguez, 929 F.2d 747, 753 n. 1 (1st Cir.1991); United States v. Day, 969 F.2d 39, 44 (3rd Cir.1992). Logic dictates therefore, that to establish such prejudice, the petitioner must begin by proving that a plea agreement was formally offered by the government. Kingsberry argues that the contradictory affidavits submitted on this issue create a fact dispute, mandating an evidentiary hearing. We disagree.
The record before this Court is sufficient to show conclusively that a formal plea offer never materialized. The two parties necessarily privy to a plea offer and fundamental to resolution of this issue both deny the existence of a plea agreement offer.5 Kingsberry argues nonetheless, that this type of trial by affidavit is proscribed by Rule 7 of the Rules Govern*1033ing § 2254 where the outcome of the proceeding rests upon the credibility of the affiant.6 While we agree with the principle enunciated by Kingsberry, we note that an evidentiary hearing is necessary only where “the court is presented with some reason to question the evidence’s credibility.” 1 Liebman and Hertz, Federal Habe-as Corpus Practice and Procedure § 19.5, at 723 (3rd ed.1998). No facts casting genuine doubt upon the veracity of Mr. Price’s affidavit were presented.
By contrast however, the veracity of Kingsberry’s own supporting affidavits can be challenged as they recite inconsistent facts regarding the substance of the alleged plea agreement offer.7 It is well settled in this Circuit that “a single, self-serving, self-contradicting statement is insufficient to render the motion, files, and records of [the] case inconclusive.... ” Holloway v. United States, 960 F.2d 1348, 1358 (8th Cir.1992). See also Smith v. United States, 618 F.2d 507, 510 (8th Cir.1980) (stating that the mere recitation of unsupported conclusions will not suffice to necessitate an evidentiary hearing). Accordingly, we cannot say that the district court abused its discretion in denying Kingsberry’s motion without an evidentia-ry hearing.
Kingsberry argues alternatively that even in the absence of a plea agreement offer, Mr. Price was constitutionally ineffective in not advising him to plead guilty. Kingsberry contends that because of Mr. Price’s erroneous calculations regarding his classification as a career offender he forwent the opportunity to plead guilty and possibly receive a downward adjustment for acceptance of responsibility. Kingsberry asserts that an evidentiary hearing is necessary to determine the substance of Mr. Price’s recommendations. We have carefully reviewed this claim and the affidavits submitted in support and in opposition, and applying similar reasoning, we conclude that the district court did not abuse its discretion in denying relief without an evidentiary hearing.
Accordingly, we affirm the judgment of the district court.
. The Honorable Scott 0. Wright, United States District Judge for the Western District of Missouri.
. The district court properly granted the government's motion for expansion of the record, to include these affidavits. See 28 U.S.C. § 2255, Rule 7 (1994) (stating in pertinent part that “[affidavits may be submitted and considered as a part of the record”).
. The record on appeal contains no affidavit by the government reciting that it never offered Kingsberry’s trial counsel a formal plea agreement. Yet, the government's appellate counsel, who also tried the case, argues as though such an affidavit was submitted to the district court. We assume that the omission of this affidavit resulted from a technical oversight, rather than dissembling, on the part of the government. If, however, government counsel who dealt with Kingsberiy's trial counsel at the time of the proffer is unable to state under oath that no such plea agreement was offered, then we expect the government to file a petition for rehearing admitting that fact and urging us to remand for an evidentiary hearing.
. Section 4A1.2(2) states in relevant part that "[plrior sentences imposed in related cases are to be treated as one sentence....” Application Note 3 states that "[p]rior sentences are not considered related if they were for offenses that were separated by an intervening arrest (i.e., the defendant is arrested for the first offense prior to committing tire second offense). Otherwise, prior sentences are considered related if they resulted from offenses that ... were consolidated for trial or sentencing ." Section 4A1.2 is relevant by virtue of Application Note 3 to § 4B1.2.
. As we noted, see supra note 3, our opinion assumes that the omission of a sworn government affidavit formally denying this was inadvertent.
. The Advisory Committee Note to 28 U.S.C. § 2254, Rule 7 is made applicable by reference from the Advisory Committee Note to 28 U.S.C. § 2255, Rule 7. "When the issue is one of credibility, resolution on the basis of affidavits can rarely be conclusive, but that is not to say they may not be helpful.” See 28 U.S.C. § 2254, Rule 7 advisory committee’s note (1994) (quoting Raines v. United States, 423 F.2d 526, 530 (4th Cir.1970)).
. Mrs. Kingsberry avers that Mr. Price communicated a plea agreement offer reducing Kingsberry's sentence from approximately twenty-two years to approximately five. See Appellant’s Ex.App. at 14-15. By contrast, Kingsberry’s affidavit stated that he believed the plea offer would reduce his base offense level from 34 to 32 (equivalent approximately to fifteen years reduced from twenty). See Appellant's Ex.App. at 13.