Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-976_e29g.pdf
Page Number: 37

Cite as:  602 U. S. ____ (2024) 

13 

SOTOMAYOR, J., dissenting 

automatic  rifle  like  an  M16,  that  automation  is  internal.  
After a shooter pulls the trigger, if he maintains continuous 
backward  pressure  on  the  trigger,  the  curved  lever  itself 
will not move.  Instead, an internal mechanism allows con-
tinuous fire.  On a bump-stock-equipped semiautomatic ri-
fle,  the  automation  is  external.    After  a  shooter  pulls  the 
trigger, if he maintains continuous forward pressure on the 
gun, the bump stock harnesses the recoil to move the curved 
lever back and forth against his finger.  That external au-
tomated motion creates continuous fire. 
  When  a  shooter  “bump”  fires  a  semiautomatic  weapon 
without a bump stock, he must control several things using 
his own strength and skill: (1) the backward recoil of each 
shot, including both the direction in which the rifle moves 
and how far it moves when recoiling; (2) the trigger finger, 
by  maintaining  a  stationary  position  with  a  loose  enough 
hold on the trigger that the rapidly moving gun will hit his 
finger each time; and (3) the forward motion of the rifle af-
ter it recoils backward.  A bump stock automates those pro-
cesses.    The  replacement  stock  controls  the  direction  and 
distance of the recoil, and the finger rest obviates the need 
to maintain a stationary finger position.  All a shooter must 
do is rest his finger and press forward on the front grip or 
barrel for the rifle to fire continuously. 
  The majority nevertheless concludes that a bump-stock-
equipped semiautomatic rifle requires too much human in-
put to fire “automatic[ally]” because it requires the “proper 
amount of forward pressure on the front grip” to maintain 
continuous fire.  Ante, at 16.  “Automati[c],” however, does 
not mean zero human input.  An M16 requires the shooter 
to exert the “proper amount of [backward] pressure on the” 

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semiautomatic rifle, however, the Model 37 does not automate the first, 
as the shooter “must manually operate the pump action with his nontrig-
ger hand” to “ejec[t ] the spent cartridge and loa[d ] a new one into the 
chamber.”  Ibid.