Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-976_e29g.pdf
Page Number: 31.0

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

7 

SOTOMAYOR, J., dissenting 

and n. 5.  Then, shifting focus from the internal mechanism 
of  the  gun  to  the  perspective  of  the  shooter,  the  majority 
holds that continuous forward pressure is too much human 
input  for  bump-stock-enabled  continuous  fire  to  be  “auto-
matic.”  See ante, at 14–17. 
  The  majority’s  reading  flies  in  the  face  of  this  Court’s 
standard tools of statutory interpretation.  By casting aside 
the statute’s ordinary meaning both at the time of its enact-
ment and today, the majority eviscerates Congress’s regu-
lation of machineguns and enables gun users and manufac-
turers to circumvent federal law. 

A 
  Start with the phrase “single function of the trigger.”  All 
the  tools  of  statutory  interpretation,  including  dictionary 
definitions,  evidence  of  contemporaneous  usage,  and  this 
Court’s prior interpretation, point to that phrase meaning 
the initiation of the firing sequence by an act of the shooter, 
whether via a pull, push, or switch of the firing mechanism.  
The majority nevertheless interprets “function of the trig-
ger” as “the mode of action by which the trigger activates 
the  firing  mechanism.”    Ante,  at  7.    Because  in  a  bump-
stock-equipped  semiautomatic  rifle,  the  trigger’s  internal 
mechanism must reset each time a weapon fires, the major-
ity reads each reset as a new “function.”  That reading fix-
ates  on a  firearm’s  internal  mechanics  while  ignoring  the 
human act on the trigger referenced by the statute. 
  Consider  the  relevant  dictionary  definitions.    In  1934, 
when  Congress  passed  the  National  Firearms  Act,  “func-
tion” meant “the mode of action by which [something] fulfils 
its  purpose.”    4  Oxford  English  Dictionary  602  (1933).    A 
“trigger” meant the “movable catch or lever” that “sets some 
force or mechanism in action.”  11 id., at 357.  The majority 
agrees with those definitions.  Ante, at 7.  It errs, however, 
by maintaining a myopic focus on a trigger’s mechanics ra-
ther  than  on  how  a  shooter  uses  a  trigger  to  initiate  fire.