Montana Pepper Spray and Stun Gun Laws (2026)

Montana's weapons statutes, Title 45, chapter 8, part 3 of the Montana Code Annotated, contain no section written specifically for pepper spray or stun guns. Most of the part's roughly 45 sections define "weapon" narrowly for a specific offense, naming firearms or a short enumerated list, and pepper spray and stun guns never appear on those lists. Several sections still reach beyond that narrow list with an open catchall, though: the possession-by-a-prisoner-or-youth offense ends its enumerated list with "or other deadly weapon," an undefined term, and the school-weapons offense adds "any other article or instrument possessed with the purpose to commit a criminal offense." The chapter's "destructive device" definition is open-ended too ("includes but is not limited to"), but its five listed categories are all ordnance, projectiles, bombs, large-caliber weapons, rockets, and incendiary devices, so the separate 10-year felony it feeds does not reach either device. Montana's local-preemption clause is also broadly worded, "any weapon," not just firearms, but its second subsection hands cities and counties back the power to bar carrying any weapon into a publicly owned and occupied building, which on the same reading would include these two.

Jurisdiction scope: This page covers Montana state law only, principally MCA 45-8-315, 45-8-316, 45-8-318, 45-8-321, 45-8-328, 45-8-332, 45-8-334, 45-8-351, 45-8-356, 45-8-361, 45-5-213, and 45-2-101. It does not cover municipal ordinances (beyond what MCA 45-8-351 itself permits) or Montana's general assault statutes outside Title 45.

Is pepper spray legal in Montana?

Montana's weapons part does not contain a section devoted to pepper spray, and enumerating the part's sections shows why there is little to find in Part 3 specifically. MCA 45-8-316 bars carrying or bearing a "firearm" concealed upon the person, naming the device directly rather than through a defined term, and a person eligible to possess a firearm under state or federal law is exempted from the offense entirely by subsection (3). MCA 45-8-321 (permit to carry a concealed weapon) is scoped by MCA 45-8-315's definition of "concealed weapon," which is limited to "a firearm that is wholly or partially covered by the clothing or wearing apparel of the person carrying or bearing the weapon." Because both provisions reach only a firearm, one by its own text and the other by that defined term, neither the concealed-carry offense nor the concealed-weapon permit system in Part 3 reaches pepper spray. No age minimum, capacity or formula cap, or purchase restriction for pepper spray appears anywhere in the part's text.

That does not mean Montana law is silent on using pepper spray against someone. Title 45's general definitions section, MCA 45-2-101(79), defines "weapon" broadly for the criminal code as a whole: "an instrument, article, or substance that, regardless of its primary function, is readily capable of being used to produce death or serious bodily injury." MCA 45-5-213, assault with a weapon, uses that general definition: purposely or knowingly causing bodily injury to another with a weapon, or a reasonable apprehension of serious bodily injury by use of a weapon or what reasonably appears to be one, is a felony punishable by imprisonment in the state prison for up to 20 years or a fine of up to $50,000, or both, with a mandatory counseling-assessment requirement added under subsection (2)(b) when the defendant is a partner or family member of the victim. Neither statute's text says whether an ordinary self-defense pepper spray canister meets the "weapon" definition, but if it does, unjustified use of it against another person carries that felony's exposure, not merely a misdemeanor.

Are stun guns legal in Montana?

The same reading largely applies to stun guns and tasers. None of Part 3's roughly 45 sections, covering machine guns, concealed firearms, permits and their denial or revocation, explosives, silencers, sawed-off firearms, firing restrictions, and school weapons, names a stun gun, taser, or electronic or electric weapon by name. As with pepper spray, the part's concealed-weapon framework (MCA 45-8-315, 45-8-316, 45-8-321, and the prohibited-place offense in MCA 45-8-328) is scoped to "concealed weapon" as defined in 45-8-315, a firearm-only definition, so it does not reach a stun gun either. No age minimum, permit requirement, or prohibited-persons list specific to stun guns appears in the part's text, and MCA 45-5-213's felony assault-with-a-weapon exposure applies to an unjustified use of a stun gun on another person the same way it could apply to pepper spray.

More than one place in Part 3 raises the question of a stun gun by an open catchall rather than a firearm-only definition, though the answer differs by section. MCA 45-8-318 makes it a felony, punishable by imprisonment in the state prison for 5 to 15 years or a fine of up to $50,000, or both, for a person committed to a state prison or incarcerated in a jail, or a youth in a detention or correctional facility, to possess a "dirk, dagger, pistol, revolver, slingshot, sword cane, billy, knuckles made of any metal or hard substance, knife, razor not including a safety razor, or other deadly weapon" without lawful authority while in custody. That closing "or other deadly weapon" phrase is open-ended, but Montana's code defines "weapon" in MCA 45-2-101(79) and never defines "deadly weapon" anywhere in the criminal code, so whether a stun gun or a spray canister smuggled into a Montana jail or youth facility falls within it is an open question the statute's wording raises rather than settles, even though neither device is named. Separately, MCA 45-8-332(1)'s "destructive device" definition, which governs the whole chapter rather than one section, opens with "includes but is not limited to" before five listed categories: a projectile containing an explosive or incendiary material or similar chemical substance, whose illustrative content is "that which is commonly known as tracer or incendiary ammunition", so the similar chemical substances the subdivision reaches are those similar to explosive or incendiary material; a bomb or similar explosive device; a weapon over .60 caliber; a rocket or rocket-propelled projectile over 0.60 inch in diameter; and a wick-equipped container of flammable liquid. Every category describes ordnance rather than a handheld aerosol canister or an electronic device, so neither pepper spray nor a stun gun qualifies, and MCA 45-8-334's separate felony for possessing a destructive device with the purpose to commit a felony, possessed in a public place, punishable by up to 10 years in the state prison or a fine of up to $50,000, or both, does not reach either device.

Local ordinances and preemption

Montana's local-preemption clause reaches further than a firearms-only reading of its title would suggest, and it also gives local governments back more authority than a first read of subsection (1) alone would suggest. MCA 45-8-351(1) states that, except as provided in subsection (2), "a county, city, town, consolidated local government, or other local government unit may not prohibit, register, tax, license, or regulate the purchase, sale or other transfer... ownership, possession, transportation, use, or unconcealed carrying of any weapon, including a rifle, shotgun, handgun, or concealed handgun." The examples that follow "any weapon" are introduced by "including," language that does not narrow the preemption to only those listed firearm types. Part 3 does not separately define "weapon" for this section, so whether "any weapon" in 45-8-351 reaches pepper spray or a stun gun turns on Title 45's general definition in MCA 45-2-101(79), "an instrument, article, or substance that, regardless of its primary function, is readily capable of being used to produce death or serious bodily injury."

Subsection (2) is where the exception lives, and it is broader than a firearms carve-out too. MCA 45-8-351(2)(a) allows a city or town to "regulate the discharge of rifles, shotguns, and handguns" for public safety, and separately gives "a county, city, town, consolidated local government, or other local government unit" the power "to prevent and suppress the carrying of unpermitted concealed weapons or the carrying of unconcealed weapons to a publicly owned and occupied building under its jurisdiction." That second grant of power is not limited to firearms, so on the same "any weapon" reading that makes the preemption clause reach pepper spray and stun guns, this exception lets a Montana city or county bar carrying either device, concealed or unconcealed, into a publicly owned and occupied building it controls, such as a city hall, courthouse, or public library. Subsection (2)(b) preserves the right to display firearms at shows and to transport firearms through a jurisdiction, a protection limited to firearms by its own text.

Where you can't carry either device

Montana's school-weapons statute, MCA 45-8-361, makes it an offense, punishable by a fine of up to $500 or up to 6 months in county jail, or both, to purposely and knowingly possess, carry, or store a "weapon" in a school building, and makes it a separate offense for a parent or guardian to knowingly permit a minor to do so. The statute defines "weapon" for this section only: "any type of firearm, a knife with a blade 4 or more inches in length, a sword, a straight razor, a throwing star, nun-chucks, or brass or other metal knuckles. The term also includes any other article or instrument possessed with the purpose to commit a criminal offense." Pepper spray and stun guns do not appear on the enumerated list, but that closing catchall clause means either device could still be reached in a school building if it were possessed for the purpose of committing a crime there, as opposed to ordinary self-defense carry. The offense does not apply to law enforcement personnel or a contracted school marshal, and district trustees may grant advance permission to possess, carry, or store a weapon in a school building. A weapon involved in a violation may be seized and, on conviction, forfeited to the state or returned to its lawful owner. "School building" is defined narrowly too: buildings owned or leased by a local school district used for instruction or student activities, expressly excluding a home school.

Separately, MCA 45-8-328 makes it an offense, punishable by up to 6 months in the county jail or a fine of up to $500, or both, for anyone other than a permit holder under 45-8-321 or 45-8-312, or a person recognized under 45-8-329, to purposely or knowingly carry a concealed weapon, defined by 45-8-315 as a firearm, into restricted state or local government office space. That offense reaches only a firearm, so it does not reach pepper spray or a stun gun. MCA 45-8-356 works differently: it is not itself a crime and sets no penalty. It is a statewide protection for a current, valid concealed-weapon permit holder, providing that such a person "may not be prohibited or restricted from exercising that permit anywhere in the state" except at eight listed categories of places, among them a correctional or detention facility, a TSA security checkpoint at a commercial airport, a federal building, a military reservation, private property whose owner or tenant prohibits firearms, a courtroom or courthouse area under a judge's order, and a school building under 45-8-361. Because it protects a firearm permit rather than prohibiting anything, it never applied to a spray or stun gun carrier in the first place; there was no permit for either device to lose. As discussed above, a jail or youth detention facility carries its own, broader exposure under MCA 45-8-318, which is not limited to firearms.

Federal law: what it does and does not reach

No federal statute regulates a civilian's purchase or possession of pepper spray or a stun gun. Federal law matters in three places.

Federal buildings. Under 18 U.S.C. § 930(a), whoever knowingly possesses or causes to be present "a firearm or other dangerous weapon in a Federal facility (other than a Federal court facility)" faces a fine, imprisonment of up to 1 year, or both. Subsection (e) sets up to 2 years for a federal court facility, and subsection (b) up to 5 years where the weapon is intended to be used in a crime. Section 930(g)(2) defines the term:

The term "dangerous weapon" means a weapon, device, instrument, material, or substance, animate or inanimate, that is used for, or is readily capable of, causing death or serious bodily injury, except that such term does not include a pocket knife with a blade of less than 2½ inches in length.

The definition names neither device. Whether a particular spray or stun gun is "readily capable of" causing serious bodily injury is a question of fact the statute does not answer. Subsection (d)(3) exempts "the lawful carrying of firearms or other dangerous weapons in a Federal facility incident to hunting or other lawful purposes," and subsection (h) requires notice of the ban to be posted at each public entrance. A "Federal facility" is "a building or part thereof owned or leased by the Federal Government, where Federal employees are regularly present for the purpose of performing their official duties."

Air travel. The Transportation Security Administration's screening rules, which are agency policy rather than statute, bar both devices from carry-on bags. One 4 fl. oz. (118 ml) container of mace or pepper spray is permitted in checked baggage if it has a safety mechanism to prevent accidental discharge, and sprays containing more than 2 percent by mass of tear gas (CS or CN) are prohibited in checked baggage. Tasers, stun guns and other electro-shock weapons may travel in checked baggage only if transported so the device cannot discharge accidentally. Airlines may set stricter rules.

National parks. National Park Service regulations prohibit possessing, carrying or using a "weapon" in a park area except as the regulations provide (36 CFR 2.4(b)(1)). 36 CFR 1.4 defines "weapon" to include an "irritant gas device" and any "weapon the possession of which is prohibited under the laws of the State in which the park area or portion thereof is located."

Disclaimer: This article provides general legal information about Montana's pepper spray and stun gun laws as of September 2026. It is not legal advice. Consult a lawyer licensed in Montana for advice about a specific situation.

For a state-by-state comparison, see pepper spray and stun gun laws by state. Montana's self-defense statutes are covered separately on the Montana self-defense laws page.

Statutes cited reflect their in-force version as of 2026-09-18. Last updated: 2026-09-18.