Who is affected and how:

• State and local governments: Lose the ability to adopt or enforce any new or existing regulations on rifles, shotguns, specified parts, or covered accessories that are stricter than federal law. Local ordinances that conflict with the federal rule would be void.
• Individuals who own or possess rifles/shotguns and certain accessories: Likely benefit from reduced risk of new state/local restrictions, bans, registration, licensing, taxes, or fees that would have been more restrictive than federal law.
• Firearms sellers, manufacturers, and dealers: Likely gain from a more uniform regulatory environment across states for the covered items, with fewer varying local restrictions.
• Courts and litigants: Expect increased litigation over alleged violations and preemption claims because the law mandates fee awards to prevailing plaintiffs, which can encourage private enforcement suits.
• Public safety officials and local policymakers: May have reduced local tools for addressing gun policy preferences or perceived local public-safety needs; they could be constrained from enacting measures they consider necessary locally.

Overall, the provision centralizes authority over covered rifles/shotguns and certain accessories at the federal level by forbidding state/local measures that are more restrictive than federal law, and it creates a legal and financial incentive for private parties to challenge local laws that run afoul of the new rule.