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Page Number: 10

6 

GARLAND v. CARGILL 

Opinion of the Court 

that §5845(b) is ambiguous as to whether a semiautomatic 
rifle equipped with a bump stock fits the statutory defini-
tion of a machinegun.  And, the majority concluded that the 
rule of lenity required resolving that ambiguity in Cargill’s 
favor.    Id.,  at  469;  see  also  id.,  at  450,  n.    An  eight-judge 
plurality  determined  that  the  statutory  definition  of  “ma-
chinegun” unambiguously excludes such weapons.  A semi-
automatic  rifle  equipped with  a  bump stock,  the plurality 
reasoned, fires only one shot “each time the trigger ‘acts,’ ” 
id., at 459, and so does not fire “more than one shot . . . by 
a  single  function  of  the  trigger,”  §5845(b).    The  plurality 
also concluded that a bump stock does not enable a semiau-
tomatic rifle to fire more than one shot “automatically” be-
cause  the  shooter  must  “maintain  manual,  forward  pres-
sure on the barrel.”  Id., at 463. 
  We granted certiorari, 601 U. S. ___ (2023), to address a 
split among the Courts of Appeals regarding whether bump 
stocks meet §5845(b)’s definition of “machinegun.”2  We now 
affirm. 

II 
  Section  5845(b)  defines  a  “machinegun”  as  any  weapon 
capable of firing “automatically more than one shot . . . by 
a single function of the trigger.”  We hold that a semiauto-
matic  rifle  equipped  with  a  bump  stock  is  not  a  “ma-
chinegun” because it cannot fire more than one shot “by a 
single function of the trigger.”  And, even if it could, it would 
not do so “automatically.”  ATF therefore exceeded its stat-
utory  authority  by  issuing  a  Rule  that  classifies  bump 
stocks as machineguns. 

—————— 

2

 See, e.g., Hardin v. Bureau of Alcohol, Tobacco, Firearms and Explo-
sives, 65 F. 4th 895 (CA6 2023);  Guedes v. Bureau of Alcohol, Tobacco, 
Firearms and Explosives, 45 F. 4th 306 (CADC 2022); Aposhian v. Barr, 
958 F. 3d 969 (CA10 2020).