Illegal firearms in Maryland fall into several buckets: 45 assault weapons named by statute (plus their copies), semi-automatic rifles, pistols, and shotguns that hit certain feature combinations, short-barreled rifles and shotguns held outside narrow exceptions, unserialized “ghost guns,” rapid-fire trigger devices, and large-capacity magazines when manufactured, sold, or transferred. Separate rules bar certain people from possessing any firearm at all, even ones that would otherwise be legal.
The 45 Named Assault Weapons
Maryland’s definition of “regulated firearm” sweeps in every handgun plus 45 specifically named assault weapons and their copies, no matter who manufactures them.1Maryland General Assembly. Maryland Code Public Safety 5-101 – Definitions Transporting one of these into the state, or possessing, selling, or receiving one, is illegal.2Maryland General Assembly. Maryland Code Criminal Law 4-303
The named list runs from the AK-47 in all forms and the Colt AR-15 (the Sporter H-BAR rifle is excluded) to shotguns like the Street Sweeper and Striker 12 and carbines like the UZI 9mm and Bushmaster semi-auto.1Maryland General Assembly. Maryland Code Public Safety 5-101 – Definitions “Copies” is doing real work in the statute. A functionally identical version of a listed weapon sold under a different brand name is still banned.
There is one narrow grandfathering path. If you lawfully possessed an assault weapon before October 1, 2013, and registered it with the state, you can keep it. Anyone who missed that registration deadline lost the window permanently.
Copycat Weapons and Feature-Based Bans
A firearm can be illegal in Maryland even if it isn’t on the named list. “Copycat weapon” rules ban guns based on combinations of features. A semi-automatic centerfire rifle qualifies as a copycat weapon if it accepts a detachable magazine and has any two of the following: a folding stock, a grenade or flare launcher, or a flash suppressor.3Maryland General Assembly. Maryland Code Criminal Law 4-301 – Definitions
A semi-automatic centerfire rifle is also a copycat weapon if it has a fixed magazine holding more than 10 rounds or an overall length under 29 inches. The label extends to any semi-automatic pistol with a fixed magazine holding more than 10 rounds, any semi-automatic shotgun with a folding stock, and any shotgun with a revolving cylinder.4Maryland State Police. Maryland Criminal Law Code 4-301 – Definitions of a Copycat Weapon
The practical effect matters if you build or modify. Swapping in certain accessories or internal parts can push an otherwise legal firearm into prohibited territory, so every feature combination needs to be checked against the statute before installation.
Short-Barreled Rifles and Shotguns
Possession of a short-barreled rifle or short-barreled shotgun is generally prohibited in Maryland.5Maryland General Assembly. Maryland Code Public Safety 5-203 – Possession of Short-Barreled Rifle or Short-Barreled Shotgun The statute carves out a few narrow exceptions:
- Federal, state, and local law enforcement on official business, plus wardens and correctional officers at Maryland facilities.
- Members of the armed forces or National Guard while on duty or traveling to or from duty.
- A short-barreled rifle or shotgun registered with the federal government under the National Firearms Act, which requires a $200 tax stamp and ATF approval before the item can be made or transferred.6ATF. National Firearms Act
Stabilizing braces complicate this. The Biden-era ATF rule reclassifying many braced pistols as short-barreled rifles was vacated in court, but the ATF has said it still enforces its longstanding interpretation that certain braced firearms qualify as unregistered short-barreled rifles, a federal felony carrying up to 10 years in prison.7Maryland General Assembly. Maryland Code Public Safety 5-203 If you own a braced firearm in Maryland, get specific legal advice before assuming you’re clear.
Rapid-Fire Trigger Activators
Any device designed to increase a firearm’s rate of fire is banned. The statute names bump stocks, trigger cranks, hellfire triggers, binary trigger systems, burst trigger systems, and auto-sears, and the definition also picks up any copy or similar device regardless of manufacturer.3Maryland General Assembly. Maryland Code Criminal Law 4-301 – Definitions Manufacturing, possessing, selling, purchasing, or transporting one of these devices into the state is illegal.8Maryland General Assembly. Maryland Code Criminal Law 4-305.1 – Rapid Fire Trigger Activator
There is no grandfathering here. Unlike the large-capacity magazine rule below, simple possession of a device you already own is not exempt. If it’s designed to speed up firing, it’s illegal in Maryland.
Ghost Guns and Unfinished Frames
Since June 1, 2022, Maryland has prohibited untraceable firearms and unfinished frames or receivers that lack serial numbers. Senate Bill 387 added a new subtitle to the Public Safety Article requiring registration of any privately made firearm.9Maryland State Police. Untraceable Firearms The target is so-called “ghost guns” built from unfinished parts kits, which have historically been difficult for law enforcement to trace.
Federal law separately punishes possession of a firearm with a removed or obliterated serial number by up to five or ten years in prison depending on the specific violation.10Department of Justice. Quick Reference to Federal Firearms Laws Maryland’s statute reaches further by covering the unfinished components before they’re assembled.
Large-Capacity Magazines and Prohibited Ammunition
Manufacturing, selling, purchasing, or transferring any detachable magazine that holds more than 10 rounds is prohibited in Maryland.11Maryland General Assembly. Maryland Code Criminal Law 4-305 – Detachable Magazines – Prohibited Possessing a large-capacity magazine you already own is not itself a crime under state law. Using one during a felony or crime of violence, however, triggers a mandatory minimum sentence of five years on top of the underlying penalty, and a second offense doubles the minimum to ten.
Anyone barred from possessing a regulated firearm is also barred from possessing ammunition. That violation is a misdemeanor carrying up to one year in jail and a $1,000 fine.12Maryland General Assembly. Maryland Code Public Safety 5-133.1 – Restrictions on Possession of Ammunition
Federal law adds a ban on armor-piercing handgun ammunition. That covers projectiles made entirely from hard metals like tungsten alloys, steel, brass, bronze, beryllium copper, or depleted uranium, along with larger-caliber handgun projectiles carrying heavy metal jackets. Standard hunting, target, and industrial ammunition is excluded from the definition.13Legal Information Institute. 18 U.S. Code 921 – Definition of Armor Piercing Ammunition
People Who Cannot Possess a Firearm
A firearm can be perfectly legal in itself and still illegal for a specific person to hold. Maryland bars several categories from possessing any regulated firearm:
- People convicted of a disqualifying crime, which covers felonies, crimes of violence, and misdemeanors carrying a statutory penalty of more than two years.
- People found to be habitually addicted to alcohol or controlled substances.
- People with a mental disorder and a history of violent behavior, or who have been confined to a mental health facility for more than 30 consecutive days, unless a physician’s certificate clears them.
- People under a protective order.
- Fugitives from justice.
- Juveniles adjudicated delinquent for acts that would be disqualifying crimes if committed by an adult, until they turn 30.
Penalties depend on the disqualifying category. For someone with a prior conviction for a crime of violence or certain drug offenses, possession carries a mandatory minimum of five years and a maximum of fifteen, and the court cannot suspend the mandatory minimum.14Maryland General Assembly. Maryland Code Public Safety 5-133 If more than five years have passed since you finished the sentence for your most recent qualifying conviction, the mandatory minimum becomes discretionary.
Federal law adds a separate ban for anyone convicted of a misdemeanor crime of domestic violence, even where the state statute didn’t label the offense that way. What matters is whether the crime involved the use or attempted use of physical force against a spouse, former spouse, co-parent, or someone in a similar domestic relationship. This prohibition applies regardless of when the conviction occurred.
Bringing Firearms Through Maryland
One boundary worth flagging for out-of-state owners: the federal Firearm Owners’ Protection Act offers limited protection when you’re passing through Maryland with a firearm legal in both your departure and destination states. The firearm must be unloaded and stored so it is not readily accessible from the passenger compartment. In a vehicle without a trunk or separate cargo area, it must be in a locked container other than the glove compartment or center console.15Office of the Law Revision Counsel. 18 U.S. Code 926A – Interstate Transportation of Firearms
FOPA covers genuine through-travel only. Stops for anything beyond fuel and basic necessities can forfeit the safe harbor, and FOPA offers nothing if the firearm is unlawful in either your departure or destination state. Bringing a Maryland-banned assault weapon, copycat weapon, short-barreled rifle, rapid-fire device, or large-capacity magazine into the state outside FOPA’s narrow window puts you in the same position as a resident who possessed it here.