Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-976_e29g.pdf
Page Number: 23.0

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

19 

Opinion of the Court 

  The dissent’s additional  argument for applying the pre-
sumption against ineffectiveness fails on its own terms.  To 
argue that  our interpretation  makes  §5845(b) “far  less  ef-
fective,” the dissent highlights that a shooter with a bump-
stock-equipped rifle can achieve a rate of fire that rivals tra-
ditional machineguns.  Post,  at  16.   But, the  dissent  else-
where acknowledges that a shooter can do the same with an 
unmodified semiautomatic rifle using the manual bump-fir-
ing technique.  See post, at 5.  The dissent thus fails to prove 
that our reading makes §5845(b) “far less effective,” much 
less ineffective (as is required to invoke the presumption).  
In any event, Congress could have linked the definition of 
“machinegun”  to  a  weapon’s  rate  of  fire,  as  the  dissent 
would prefer.  But, it instead enacted a statute that turns 
on whether a weapon can fire more than one shot “automat-
ically . . . by a single function of the trigger.”  §5845(b).  And, 
“it is never our job to rewrite . . . statutory text under the 
banner  of  speculation  about  what  Congress  might  have 
done.”  Henson v. Santander Consumer USA Inc., 582 U. S. 
79, 89 (2017).9 

III 
  For the foregoing reasons, we affirm the judgment of the 
Court of Appeals. 

It is so ordered. 

—————— 

9

 The dissent concludes by claiming that our interpretation of §5845(b) 
“renders Congress’s clear intent readily evadable.”  Post, at 17.  And, it 
highlights that “[e]very Member of the majority has previously empha-
sized that the best way to respect congressional intent is to adhere to the 
ordinary understanding of the terms Congress uses.”  Ibid.  But, “[w]hen 
Congress takes the trouble to define the terms it uses, a court must re-
spect its definitions as virtually conclusive. . . . This Court will not devi-
ate from an express statutory definition merely because it varies from 
the term’s ordinary meaning.”  Department of Agriculture Rural Devel-
opment Rural Housing Service v. Kirtz, 601 U. S. 42, 59 (2024) (internal 
quotation marks and alteration omitted) (unanimous opinion).