I'm no expert on the rules for this offense. (Care to point me to the rules you are referring to?) But, as a general matter, it is in the court's discretion to impose consecutive or concurrent sentences. The guidelines may recommend concurrent sentences (if that's what you're referring to) but the court may disregard that recommendation so long as it indicates that it has considered the guideline and the usual factors that must be considered before departing from the guidelines.
For example:
> [A] district court retains discretion under 18 U.S.C. § 3584(a) and the sentencing guidelines to order that sentences be served consecutively notwithstanding the dictates of U.S.S.G. § 5G1.2. This discretion, however, is not sui generis; it is simply another manifestation of the district courts' departure power. Because this is so, a district court can only impose consecutive sentences in derogation of U.S.S.G. § 5G1.2 if it follows the accepted protocol for guideline departures.
United States v. Quinones, 26 F.3d 213, 217 (1st Cir. 1994)
I think I've determined that you're talking about offense grouping under USSG s. 3D1.2. [1] I had thought you were talking about something different: whether offenses are to be charged concurrently or consecutively. It is my strong suspicion that the 3D1.2 grouping rules are also only a recommendation (there is certainly no doubt that, generally speaking, the guidelines are not legally binding -- a district court need only consider them and the sentencing factors they articulate), but I have not found a definitive answer yet.
But this distinction -- discretion to disregard 3D1.2 v. discretion to disregard 5G1.2 [2] -- is largely academic. Section 3 of the guidelines deals with determination of the "total punishment." Section 5 deals with how to actually implement that punishment -- that is, how to use the traditional "one sentence per count" approach to implement the guidelines' "total punishment" approach. When there are multiple counts/offenses of conviction, the district court groups the offenses, and determines a total punishment for each group (that's 3D1.2). Then it implements that sentence by imposing it for each count (note: not "group") of conviction, to run concurrently. (5G1.2) But, under Quinones (in the First Circuit) it appears clear that a district court, after adequate explanation, may depart from the 5G1.2 methodology and impose the "total punishments" consecutively instead of concurrently. So, even if grouping under 3D1.2 remains mandatory (which I doubt), it would seem that the court would still be free to depart from the implementation methodology provided in 5G1.2 to impose that "total punishment" more than once, consecutively. Here that means that even if the district court grouped all five counts together and arrived at a total punishment of seven years, under 3D1.2, it could still impose that sentence five times, consecutively, under 5G1.2.
It's worth emphasizing that it would be quite unusual for a judge to do this, and she would have to quite clearly articulate her reasons for doing so in order for the sentence to not be vacated on appeal. This, I suspect, is why Popehat, for example, describes the operation of the guidelines as though it were mandatory -- typically an attorney can take for granted the fact that a judge will follow them or, at any rate, not depart too wildly. If you are trying to make a realistic prediction/determination of a defendant's sentence, the guidelines are where you look. But it also remains true that a district court may, with adequate justification, disregard the guidelines and have the sentence affirmed on appeal -- this includes the possibility here, however remote, of five statutory maximum sentences all to run consecutively.
For example:
> [A] district court retains discretion under 18 U.S.C. § 3584(a) and the sentencing guidelines to order that sentences be served consecutively notwithstanding the dictates of U.S.S.G. § 5G1.2. This discretion, however, is not sui generis; it is simply another manifestation of the district courts' departure power. Because this is so, a district court can only impose consecutive sentences in derogation of U.S.S.G. § 5G1.2 if it follows the accepted protocol for guideline departures.
United States v. Quinones, 26 F.3d 213, 217 (1st Cir. 1994)