Substantial Ammunition as an Independent Basis for an Upward Variance in § 922(o) Machinegun Possession Sentencing

I. Introduction

United States v. Colon-Vazquez (1st Cir. June 26, 2026) addresses when an upwardly variant sentence for unlawful machinegun possession is procedurally and substantively reasonable under federal sentencing law. The defendant, Eddie Colón-Vázquez (“Colón”), pleaded guilty to one count of possessing a machinegun in violation of 18 U.S.C. § 922(o). Although the parties’ plea agreement contemplated recommendations of 18 months (defense) and up to 24 months (government), the district court imposed 48 months, which was an 11-month upward variance from the top of the uncontested Guidelines range (30–37 months).

On appeal, Colón argued (1) procedural unreasonableness—primarily that the district court inadequately explained why his case was outside the “heartland” of the applicable Guideline and relied on factors already accounted for; and (2) substantive unreasonableness—that the sentence was too severe for a “victim-free” firearms possession offense given his lack of criminal history. The First Circuit affirmed.

II. Summary of the Opinion

The First Circuit held that Colón’s 48-month sentence was both procedurally and substantively reasonable. Key points include:

  • The court clarified that the relevant benchmark for assessing a variance is the Guidelines range, not the parties’ sentencing recommendations.
  • Because Colón did not object to the PSR’s Guidelines calculations, the operative range was 30–37 months, and the sentence was therefore an 11-month upward variance.
  • The district court’s explanation was adequate because it relied on a combination of individualized, permissible factors (firearms, ammunition, magazines, and accompanying items), not merely the inherent dangerousness of a machinegun.
  • Importantly, the First Circuit concluded that the quantity and configuration of ammunition and high-capacity magazines alone was “independently sufficient” under circuit precedent to support the variance.
  • The sentence was substantively reasonable given the district court’s plausible rationale (deterrence, seriousness, public protection) and a defensible result within the “universe of reasonable sentencing outcomes.”

III. Analysis

A. Precedents Cited

1. Sentencing review framework and explanation duties

  • Gall v. United States, 552 U.S. 38 (2007): The backbone of the opinion’s methodology. The First Circuit followed Gall’s two-step reasonableness review (procedural then substantive) and quoted Gall’s rule that courts must “adequately explain” a chosen sentence and that justification must be proportional to the extent of the deviation.
  • United States v. Morales-Vélez, 100 F.4th 334 (1st Cir. 2024): Used repeatedly for (i) standards of review, (ii) the principle that the Guidelines—rather than plea recommendations—are the starting point, and (iii) distinguishing cases where courts relied only on machinegun dangerousness from cases supported by additional individualized facts such as ammunition quantity.
  • United States v. Montero-Montero, 817 F.3d 35 (1st Cir. 2016): Cited for the proportionality principle: the greater the deviation from the Guidelines, the greater the explanation burden.
  • United States v. Mercado-Cañizares, 133 F.4th 173 (1st Cir. 2025): Central to the holding. The court relied on Mercado-Cañizares to reaffirm that ammunition quantity (there, 74 rounds with high-capacity magazines) can be “independently sufficient” to justify the same variance imposed here (48 months from a 37-month top range).

2. “Rivera-Berríos line” and machinegun-dangerousness as an insufficient standalone rationale

  • United States v. Rivera-Berríos, 968 F.3d 130 (1st Cir. 2020), United States v. García-Pérez, 9 F.4th 48 (1st Cir. 2021), and United States v. Carrasquillo-Sánchez, 9 F.4th 56 (1st Cir. 2021): These decisions had reversed upward variances where district courts relied “solely or primarily” on the dangerousness of machineguns—a characteristic already embedded in the applicable Guideline—without sufficient added justification. Colon-Vazquez distinguishes them because the district court relied on a broader constellation of individualized facts (especially ammunition and magazines) rather than treating machinegun dangerousness as dispositive.
  • United States v. Polaco-Hance, 103 F.4th 95 (1st Cir. 2024): Provides the “safe harbor” model the panel applies: an upward variance is sustainable when the judge does not give dispositive weight to machinegun dangerousness alone but considers it with other individualized sentencing facts.

3. Ammunition and magazine quantity as a permissible upward-variance driver

  • United States v. Bruno-Campos, 978 F.3d 801 (1st Cir. 2020): The seminal ammunition-quantity rationale. The panel used it for the proposition that substantial ammunition and/or multiple high-capacity magazines—especially more than expected in a typical unlawful possession case—may justify an upward variance because the Guidelines do not directly account for that aggravation.
  • United States v. Rosario-Merced, 109 F.4th 77 (1st Cir. 2024): Reinforces that “typical unlawful possession” is the comparator and collects cases approving variances based on ammunition and magazines.

4. Guidelines error, waiver/forfeiture, and PSR reliance

  • Molina-Martinez v. United States, 578 U.S. 189 (2016): Cited to explain how unnoticed Guidelines miscalculations can be reviewed for plain error when a defendant failed to object. The panel invoked it to frame—but ultimately reject—any claim that the PSR range was wrong.
  • United States v. Severino-Pacheco, 911 F.3d 14 (1st Cir. 2018): Used both for waiver implications of failing to object to the PSR and for the idea that brevity in discussing personal factors is not necessarily “inattention.”
  • United States v. González-Rodríguez, 859 F.3d 134 (1st Cir. 2017): Supports that unobjected-to PSR facts may be relied upon at sentencing—critical to rejecting Colón’s point that he did not plead to ammunition quantities.
  • United States v. Zannino, 895 F.2d 1 (1st Cir. 1990) and United States v. Thompson, 62 F.4th 37 (1st Cir. 2023): Applied as waiver doctrines for underdeveloped arguments and issues raised only in reply.

5. Community-based deterrence considerations

  • United States v. Flores-Machicote, 706 F.3d 16 (1st Cir. 2013): Cited for the principle that sentencing judges may consider community-based and geographic crime conditions to inform deterrence.
  • United States v. Carmona-Alomar, 109 F.4th 60 (1st Cir. 2024): Tightens the rule: community-based considerations must be used in conjunction with case-specific factors. The panel found that requirement satisfied on this record.
  • United States v. Flores-González, 46 F.4th 57 (1st Cir. 2022) (Mem.): Mentioned to reflect that, at the time of sentencing, the First Circuit had withdrawn a panel opinion and was considering the topic en banc—context the district judge attempted to navigate by carefully parsing existing precedent.

6. Other doctrinal anchors

  • Kimbrough v. United States, 552 U.S. 85 (2007): Addressed only to reject Colón’s suggestion that the district court secretly imposed a policy-disagreement (“Kimbrough”) variance without notice. The panel found the record showed the defense had an opportunity to object; Colón later conceded it was not a Kimbrough variance.
  • Peugh v. United States, 569 U.S. 530 (2013): Used to emphasize that the Guidelines remain the “starting point” and can still be the “basis” for the sentence even when varying.
  • United States v. Clogston, 662 F.3d 588 (1st Cir. 2011) and United States v. Rodríguez-Cruz, 997 F.3d 362 (1st Cir. 2021): Provide the “universe of reasonable sentences” framing and the “plausible rationale/defensible result” substantive reasonableness test.
  • United States v. Sineneng-Smith, 590 U.S. 371 (2020): Cited to explain why the court would not sua sponte expand an issue (here, the district court’s debatable reliance on Valle-Colón) not pressed as a standalone ground for vacatur.

B. Legal Reasoning

1. The operative benchmark is the Guidelines range, not the plea’s recommendations

The panel reaffirmed that the sentencing “starting point” is the correctly calculated Guidelines range, and that appellate review compares the sentence to that range—not to the parties’ negotiated recommendations. This matters in practice because Colón’s rhetoric framed the district court’s sentence as “double” what the parties contemplated, but legally the variance was measured from the top of the Guidelines range.

2. Failure to object to the PSR locked in the Guidelines range—and the facts supporting it

Colón did not object to the PSR, which increased the offense level based on (i) being a “prohibited person” due to long-term marijuana use and (ii) the presence of three firearms. The First Circuit treated the PSR range as correct and additionally treated the PSR’s unchallenged factual details—especially ammunition and magazines—as proper sentencing facts.

3. Procedural reasonableness: combination-of-factors explanation and an independently sufficient factor

The court rejected the claim that the district judge failed to explain the variance. The district court identified specific facts (three firearms including two machineguns; extensive ammunition and high-capacity magazines; and accompanying items suggesting readiness for violent criminal activity) and connected them to statutory purposes (seriousness, deterrence, protection of the public, respect for law).

Critically, the First Circuit then supplied an alternative, precedent-driven validation: even if other factors were ignored, the ammunition quantity alone was “independently sufficient” under United States v. Mercado-Cañizares and related cases to justify the upward variance.

4. Addressing the “lawful ownership” analogy

Colón argued that his ammunition quantity looked ordinary in the context of lawful gun ownership (e.g., ammo sold in boxes of 50; airline transport allowances). The First Circuit rejected the comparison as misframed: the relevant benchmark is what is typical in a typical unlawful possession case, not in lawful firearms commerce. This move cements a practical rule: arguments that ammunition is legally purchasable do not negate its aggravating significance when paired with unlawful machinegun possession.

5. Community-based deterrence: allowed when tethered to individualized facts

While noting ongoing doctrinal debate at the time (referencing the en banc posture of Flores-González), the panel concluded the district court did what circuit precedent permits: it used Puerto Rico’s high homicide rate and the local context to inform deterrence, while also grounding the sentence in Colón’s individualized conduct and the items found with him.

6. A cautionary note: cross-guideline reliance on United States v. Valle-Colón

The panel flagged an analytical mismatch: the district court cited United States v. Valle-Colón for a proposition about guidelines not accounting for an “assault rifle,” but Valle-Colón involved 18 U.S.C. § 924(c) and U.S.S.G. § 2K2.4(b), whereas Colón was sentenced under 18 U.S.C. § 922(o) and U.S.S.G. § 2K2.1. The panel did not reverse on this basis because Colón did not press it as an independent ground for vacatur and, in any event, the ammunition rationale independently supported the variance.

C. Impact

1. Reinforcement—and practical extension—of the ammunition-based variance doctrine in § 922(o) cases

Although the decision is heavily precedent-driven, it operationalizes a clear, litigable takeaway: in unlawful machinegun possession cases sentenced under U.S.S.G. § 2K2.1, substantial ammunition and high-capacity magazines can be treated as an aggravating circumstance sufficient by itself to support a meaningful upward variance, even where the base offense level already reflects the weapon’s dangerousness.

2. Litigation consequences for PSR practice

The opinion underscores that defendants who do not object to PSR calculations and factual recitations face two compounding consequences on appeal: (i) the Guidelines range becomes difficult to contest, and (ii) the factual record (e.g., ammunition quantities) becomes available as sentencing support without the need for trial-level proof disputes.

3. A road map for district courts (and a warning)

  • Road map: To sustain upward variances in firearms cases, district courts should articulate individualized factors beyond the machinegun’s inherent dangerousness—especially ammunition, magazine capacity, number of firearms, and contextual evidence tied to § 3553(a).
  • Warning: The panel’s note about Valle-Colón signals that courts should avoid importing “heartland” conclusions from materially different statutes and Guidelines provisions without careful translation.

IV. Complex Concepts Simplified

  • Guidelines “range” vs. plea recommendations: The Guidelines range is the court’s principal benchmark. Parties can recommend lower or higher sentences, but those recommendations do not set the legal baseline for “variance” analysis.
  • Upward “variance” vs. “departure”: A variance is a sentence outside the Guidelines range based on the statutory factors in 18 U.S.C. § 3553(a). A departure is a Guidelines-authorized adjustment within the Guidelines framework. This case concerns a variance.
  • Procedural vs. substantive reasonableness:
    • Procedural asks whether the court used the right process—correct range, proper factor consideration, adequate explanation.
    • Substantive asks whether the outcome is defensible given the totality of circumstances.
  • “Heartland”: A shorthand for cases the Guideline is designed to cover. A court needs a principled reason to treat a case as outside the typical set—here, the court emphasized ammunition/magazines and related indicia of violent readiness.
  • Plain error review (when you didn’t object): If a defendant fails to object at sentencing, appellate review often becomes more limited. The court discussed this concept but found no Guidelines error to correct.
  • Community-based deterrence: Courts may consider local crime conditions for deterrence, but they must still tie the sentence to what the defendant did (individualized sentencing).
  • “Prohibited person” (Guidelines): Under U.S.S.G. § 2K2.1, certain statuses (including long-term unlawful drug use as described in the commentary) can increase the base offense level when firearms are involved.

V. Conclusion

United States v. Colon-Vazquez affirms an 11-month upward variance for § 922(o) machinegun possession and crystallizes a practical sentencing rule in the First Circuit: substantial ammunition and high-capacity magazines can independently justify an upward variance, especially when supported by unobjected-to PSR facts and accompanied by a reasoned § 3553(a) explanation. The decision also serves as a procedural reminder that failing to object to the PSR effectively concedes both the Guidelines framework and many of the factual building blocks that can sustain a variant sentence on appeal.