Montana Suppressor Laws in 2026: Legal to Own, but State Law Still Points to Federal Registration

By Cole Harlan, Editor · The Release Desk · Updated Oct 21, 2026 · How we verify · Editorial standards

Montana is suppressor country: ATF's own registry data counts 74,434 registered suppressors in the state. It was also one of the 15 states that sued and won in Silencer Shop Foundation v. ATF. But Montana's criminal code was written around federal registration, and ATF's October 9, 2026 decision to stop enforcing NFA registration doesn't rewrite it. Here's what the statutes say, what Attorney General Austin Knudsen told prosecutors, and what that means for buyers and hunters.

Not legal advice. This page summarizes the Montana Code Annotated, the Attorney General's August 27, 2026 guidance letter and federal guidance as of the date above. ATF's change is a non-enforcement policy, not a repeal of the National Firearms Act. Ask your dealer or a Montana attorney before you rely on a 4473-only can.

The short answer

Suppressors are legal to own in Montana. No Montana statute bans them outright. The silencer offense in MCA 45-8-336 requires a purpose to use the silencer to commit an offense.
But registration is the trigger. MCA 45-8-337 says possessing "a silencer that is not registered under federal law" is "prima facie evidence of a purpose to use the same to commit an offense." That's why we list Montana with the states whose law references federal registration.
The penalty is serious: 5 to 30 years in state prison, a fine of $1,000 to $20,000, or both (MCA 45-8-336(2)).
Hunting requires a registered can. MCA 87-6-401(1)(c) allows a suppressor while hunting only if it's "registered with the bureau of alcohol, tobacco, firearms and explosives."
A $0 voluntary Form 4 solves both problems. ATF still accepts Form 4 filings, and the tax is $0.
Change is coming. Three Republican legislators say they'll file bills in the 2027 session, which opens in January, to remove the registration-based provisions.

What Montana law says

Montana's two silencer statutes work as a pair. MCA 45-8-336(1) makes it a crime to possess, manufacture, transport, buy or sell a silencer when the person "has the purpose to use it to commit an offense or knows that another person has such a purpose." Read alone, that's a law against criminal use, not ownership.

MCA 45-8-337 changes the picture. It makes possession of an unregistered silencer "prima facie evidence" of that unlawful purpose. In practice, a prosecutor who shows that your suppressor isn't in the federal registry has made the first part of the case, and you'd be the one explaining your lawful purpose.

The Attorney General reads the pair more bluntly. His August 27, 2026 letter to Montana prosecutors, sheriffs and police chiefs is headed "Possession of a non-federally registered silencer is a felony offense under Montana law," and it says a Montanan who skips federal registration "could still be subject to felony prosecution under Montana law."

What the Attorney General told law enforcement

The August 27 letter came after the Silencer Shop ruling but before ATF's nationwide October 9 guidance, when the injunction still covered only the plaintiffs and their members. Montana was a plaintiff. Three points from the letter still matter now:

It said criminal investigations under MCA 45-8-336, 45-8-337 and 45-8-340 (sawed-off firearms) "may be tenuous given the current legal environment."
It asked city and county attorneys to send any case under those statutes, or under the hunting statute 87-6-401(1)(c), to the Montana Department of Justice Prosecution Services Bureau "for review and advisement before any charges ... are formally filed."
It said the "best interpretation" of the hunting statute's registration language "is compliance with the NFA's registration requirements," so "Montana law still requires NFA registration to hunt with a suppressor."

That's a request for central review, not a promise that no one will be charged. Until the Legislature acts, the statutes are on the books as written.

How ATF's October 9 change plays out in Montana

ATF's open letter says it will no longer enforce the NFA's approval, registration and tax-stamp rules for suppressors, SBRs, SBSs and AOWs. Its FAQ says it "cannot opine" on whether an unregistered item satisfies a state law that references registration. Montana's law does exactly that. A suppressor bought on a Form 4473 alone is lawful under federal enforcement policy, but under MCA 45-8-337 it's still "not registered under federal law."

The fix is cheap. File a voluntary Form 4 at $0, keep the approval, and your can is registered under federal law for both the criminal statute and the hunting statute.

Hunting with a suppressor in Montana

Montana has allowed hunting with a suppressor since 2015, when the Legislature amended MCA 87-6-401 (2015 Mont. Laws ch. 260). The statute still bans using "any device or mechanism devised to silence, muffle, or minimize the report of any firearm" while hunting, then carves out a device "registered with the bureau of alcohol, tobacco, firearms and explosives." The Attorney General reads that as NFA registration. Carry your Form 4 approval in the field, and check Montana Fish, Wildlife & Parks' current regulations for your species and district.

What's next: the 2027 session

Sen. Wylie Galt, Sen. Carl Glimm and Rep. Braxton Mitchell have announced identical Senate and House bills for the 2027 session to trim Montana's silencer provisions and repeal the sawed-off firearm section, the Daily Montanan reported on October 19, 2026. Attorney General Knudsen has said he's "confident we'll get this done in the 2027 session." Until a bill passes and takes effect, the current statutes apply.

Bottom line for Montana buyers

Montana is friendly to suppressors, but its law still treats federal registration as the proof of a lawful purpose. File the $0 Form 4, carry the approval when you hunt, and watch the 2027 session. Browse the new suppressors of 2026, compare Idaho next door, and read the national suppressor buying guide.

Frequently asked questions

Are suppressors legal in Montana in 2026?

Yes. Montana doesn't ban suppressors. But MCA 45-8-337 makes possession of a silencer "not registered under federal law" prima facie evidence of a purpose to commit an offense, and the Attorney General's August 27, 2026 letter calls possession of a non-registered silencer a felony under Montana law.

Can I buy a suppressor in Montana on a Form 4473 without a Form 4?

Federal enforcement policy allows it since October 9, 2026, but Montana law still references federal registration. A voluntary Form 4 costs $0 and puts the can in the federal registry, which is the safest way to own one in Montana until the Legislature changes the law.

Can you hunt with a suppressor in Montana?

Yes, with a registered one. MCA 87-6-401(1)(c) allows a suppressor while hunting if it is "registered with the bureau of alcohol, tobacco, firearms and explosives." The Attorney General reads that to mean NFA registration.

Is Montana changing its suppressor laws?

Three legislators have announced identical bills for the 2027 session, which opens in January 2027, to trim the silencer provisions and repeal the sawed-off firearm section. Nothing changes until a bill passes and takes effect.

How many registered suppressors are in Montana?

74,434, according to ATF registry data obtained by the American Suppressor Association through FOIA request 2026-01285 (fulfilled May 2026).

Sources

Supplementary sources

News reports, advocacy groups, dealer practice and unofficial copies. They add context or report statements; the primary sources above control.