United States Court of Appeals
                        For the First Circuit


Nos. 17-1144, 17-1247

                    UNITED STATES OF AMERICA,

                              Appellee,

                                 v.

                JOSHUAN DAVID CABALLERO-VÁZQUEZ,

                        Defendant, Appellant.


          APPEALS FROM THE UNITED STATES DISTRICT COURT
                 FOR THE DISTRICT OF PUERTO RICO

         [Hon. Francisco A. Besosa, U.S. District Judge]
       [Hon. Carmen Consuelo Cerezo, U.S. District Judge]


                               Before

                Torruella, Thompson, and Kayatta,
                         Circuit Judges.


     Johnny Rivera-González and Johnny Rivera's Law Office, on
brief for appellant.
     Mainon A. Schwartz, Assistant United States Attorney, Rosa
Emilia Rodríguez-Vélez, United States Attorney, and Mariana E.
Bauzá-Almonte, Assistant United States Attorney, Chief, Appellate
Division, on brief for appellee.



                            July 18, 2018
            TORRUELLA, Circuit Judge.           After pleading guilty in two

separate cases, Joshuan David Caballero-Vázquez was sentenced

first for possessing ammunition as a convicted felon (the "Felon

in Possession Case") and then for possessing a machine gun (the

"Machine    Gun   Case").        In    this   consolidated      appeal,    he   now

challenges both of those sentences on procedural and substantive

grounds.    We affirm both sentences.

                                  I. Background

            We begin with an overview of the intertwined factual and

procedural events leading up to this appeal.                 Because this appeal

follows two different guilty pleas, we draw the facts from the

plea      agreements,         change-of-plea        colloquies,      presentence

investigation reports (PSRs), and sentencing hearings in both

cases.     See United States v. Reyes-Rivera, 

, 82 (1st

Cir. 2016).

A.

            We start with the facts giving rise to the Machine Gun

Case.     On March 7, 2015, an officer from the Manatí, Puerto Rico

Municipal Police stopped Caballero-Vázquez after observing him

drive a Ford Edge against traffic, and then up onto the sidewalk.

After asking Caballero-Vázquez for his license and registration,

the officer noticed that the registration information Caballero-

Vázquez    provided     did    not    match   the   number    on   the   vehicle's


                                        -2-
registration sticker.     Suspecting a false registration sticker,

the officer seized both Caballero-Vázquez and the Ford Edge and

brought them to the Manatí Municipal Police Station.              There, an

inventory search of the vehicle yielded a loaded Glock .40 caliber

pistol that had been modified to function as a machine gun.

Moreover, a database search using the Glock's serial number would

later reveal that it had been reported as stolen from the residence

of its legal owner.

           A grand jury returned a one-count indictment against

Caballero-Vázquez for possessing a machine gun.            See 

(o), 924(a)(2).     On September 2, 2015, Caballero-Vázquez,

after entering into a type-B plea agreement with the government,

pleaded guilty to that count.      See Fed. R. Crim. P. 11(c)(1)(B).

The parties jointly calculated a guidelines range to serve as the

basis for the plea agreement's sentencing recommendation.              They

began with a base offense level of 18, see U.S.S.G. § 2K2.1(a)(5),

but then subtracted three levels because Caballero-Vázquez had

accepted responsibility, see id. § 3E1.1, thereby arriving at an

adjusted offense level of fifteen.       The parties did not stipulate

to any particular Criminal History Category (CHC).           The parties

then   agreed   to   recommend   that    the   district   court    sentence

Caballero-Vázquez to a term of imprisonment at the lower end of