Aposhian v. Barr, 374 F. Supp. 3d 1145

Plaintiff Aposhian owns a Slide Fire bump-stock-type device and challenged the ATF Final Rule classifying such devices as "machineguns" under the NFA and GCA.
The Final Rule defines "single function of the trigger" as "single pull of the trigger and analogous motions," and defines "automatically" as "the result of a self-acting or self-regulating mechanism that allows firing multiple rounds through a single pull."
Aposhian argued the definitions are incorrect: "function" refers to mechanical trigger movement (excluding bump stocks), and "automatically" requires a higher degree of shooter noninvolvement (arguing bump stocks are not automatic because they require forward pressure by the non-trigger hand).
The government defended the Final Rule as a permissible interpretation of undefined statutory terms and explained the ATF changed prior positions with rationale in the Rule.
The district court concluded the Rule’s definitions best reflected the statute and its contemporaneous meaning, rejected heightened scrutiny based on political pressure or an agency policy change, and denied Aposhian’s motion for a preliminary injunction.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Meaning of "single function of the trigger"	"Function" means mechanical trigger movement; bump stocks not covered	"Function" means shooter-focused — a single pull or analogous motion; includes bump stocks	Court: "single function" best read as "single pull of the trigger" (includes bump stocks)
Meaning of "automatically"	Requires minimal or no ongoing shooter input; bump stock involvement defeats automaticity	"Automatically" means self-acting/self-regulating mechanism allowing multiple rounds from a single pull; shooter input does not defeat automaticity	Court: Adopted dictionary-based "self-acting" definition; Final Rule is best interpretation
Agency change & political motive	Rule reflects political pressure and an unexplained policy reversal; warrants greater scrutiny	Policy changes are permissible if acknowledged and explained; Final Rule explains prior inconsistent rulings	Court: No heightened scrutiny; ATF adequately acknowledged and justified change
Entitlement to injunction	Rule invalid so injunction should issue	Plaintiff unlikely to succeed on merits; no injunction	Court: Denied preliminary injunction; plaintiff not likely to succeed

Guedes v. ATF, 356 F. Supp. 3d 109 (D.D.C. 2019) (upholding ATF authority and similar interpretation of Final Rule)
Akins v. United States, [citation="312 F. App'x 197"] (11th Cir. 2009) (construing "single function of the trigger" as a "single pull")
United States v. Olofson, 563 F.3d 652 (7th Cir. 2009) (defining "automatically" via contemporaneous dictionaries as self-acting mechanism)
F.C.C. v. Fox Television Stations, Inc., 556 U.S. 502 (2009) (agency policy changes need not trigger heightened scrutiny if adequately explained)
Lockheed Martin Corp. v. Admin. Review Bd., Dep't of Labor, 717 F.3d 1121 (10th Cir. 2013) (rejecting skepticism for agency interpretation that reflects a policy change)
United States v. White, 782 F.3d 1118 (10th Cir. 2015) (discussing deference to agency interpretations implicating criminal liability)
United States v. Apel, 571 U.S. 359 (2014) (noting Supreme Court has not granted deference to agency's internal reading of criminal statutes)
Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984) (doctrine recognizing agencies can fill statutory gaps through interpretation)