Montana Weapons & Self-Defense Laws (2026)
A comprehensive legal reference for weapons & self-defense in the state of Montana. This guide covers current statutes, penalties, and restrictions for 11 different categories.
Body Armor
RESTRICTEDBody armor is legal to purchase and wear in Montana for civilians without felony convictions. There have been no significant state-level legislative changes concerning body armor in Montana in recent years.
Ownership
Legal for civilians to purchase and possess body armor. No permit or registration required. Montana has no state-level restrictions. All types and levels are legal. Montana's strong individual rights tradition extends to defensive equipment.
Purchase
Legal to sell in-store and online. No special licensing or age restrictions.
Penalties
Felons face up to 3 years federal prison. Montana does not have specific state-level enhanced sentencing for body armor.
Age Restriction
18+
Brass Knuckles
ILLEGALMontana prohibits the possession, sale, and manufacture of brass knuckles under Mont. Code Ann. § 45-8-331. They are considered prohibited weapons except for law enforcement or military use.
Possession
Illegal to possess except for authorized persons.
Sale & Purchase
Illegal to sell or manufacture.
Penalties
Misdemeanor punishable by fines and/or imprisonment up to 6 months.
Age Restriction
None (possession is prohibited regardless of age).
Butterfly Knives
LEGALButterfly knives are legal to own and carry in Montana with no specific restrictions beyond general knife laws. The most significant recent change was the passage of a state preemption law, which nullified all local knife ordinances.
Possession
Legal
Sale & Purchase
Legal
Penalties
N/A
Age Restriction
18+ for purchase
Montana allows permitless concealed carry for residents 18 and older under Montana Code Annotated § 45-8-321. No permit is required to carry a concealed firearm if the person is legally allowed to possess one.
Permitless Carry Rules
Legal to carry concealed without a permit if 18 or older and not prohibited.
Permit Availability
Sales regulated under state and federal law; background checks required for licensed dealers.
Penalties
N/A for lawful permitless carry; penalties apply for prohibited persons carrying firearms.
Minimum Age
18 years old minimum for permitless carry.
Flamethrowers
LEGALFlamethrowers are legal to own and use in Montana with no state-level restrictions. No significant legislative changes regarding flamethrowers in recent years.
Ownership
Legal, no permit required
Purchase
Legal
Penalties
N/A
Age Restriction
No state restriction
Nunchucks
LEGALNunchucks are legal to own and possess in Montana with no specific restrictions. No significant changes in recent years.
Possession
Legal
Sale & Purchase
Legal
Penalties
N/A
Age Restriction
None
Open Carry
RESTRICTEDOpen carry of firearms is legal with restrictions in Montana without a permit for adults who are legally allowed to possess firearms. Montana expanded its permitless carry law in 2021 to cover more locations, solidifying its status as a constitutional carry state.
Open Carry Rules
Legal without permit for eligible adults
Permit Requirements
Legal through licensed dealers
Penalties
Prohibited in certain locations (schools, courthouses, etc.).
Minimum Age
18+ for long guns, 21+ for handguns
Pepper Spray Restrictions
RESTRICTEDMontana permits possession and use of pepper spray for self-defense without restrictions on size or concentration. No license or registration is required under Mont. Code Ann. § 45-8-321.
Carrying
Legal for all adults; no permit required.
Purchase
No special restrictions on sale or purchase.
Penalties
N/A
Age Restriction
18 years old minimum.
Suppressors / Silencers
RESTRICTEDSuppressors / Silencers are legal with restrictions in Montana. State law does not restrict suppressors beyond federal regulations.
Ownership (with NFA)
Legal with federal NFA registration and tax stamp.
Dealer Availability
Legal with federal compliance.
Penalties
N/A if federally compliant; otherwise, felony charges may apply.
Age Restriction
21 years or older federally required.
Montana law does not specifically restrict switchblade knives. Possession, sale, and carry of automatic knives are legal under state law, with no explicit prohibitions or restrictions.
Possession
Legal to possess switchblades.
Sale & Purchase
Legal to sell switchblades.
Penalties
N/A
Age Restriction
None.
Tasers & Stun Guns
RESTRICTEDTasers & Stun Guns are legal with restrictions in Montana. No significant legislative changes since the current laws on concealed carry and self-defense were enacted.
Ownership
Legal without permit
Purchase
Legal
Penalties
N/A
Age Restriction
18+