You can legally own a submachine gun (SMG) in Colorado if (1) you lawfully obtain an “NFA tax stamp” from the ATF (Bureau of Alcohol, Tobacco, Firearms and Explosives), and (2) the SMG was manufactured prior to May 19, 1986.

Getting an NFA tax stamp requires you to pay $200 and complete – and have approved – an ATF Form 4, Application for Tax Paid Transfer and Registration of Firearm for the particular SMG. This process can take several months.¹

1. What are submachine guns?

Abbreviated SMG, submachine guns are portable automatic firearms that discharge from the hip or shoulder and that use handgun-type ammunition. Machine guns tend to be larger and have more firepower than submachine guns because machine guns use rifle ammunition.

SMGs were originally developed for WWI. The military still uses them. The most famous SMG model is the Thompson submachine gun, nicknamed the Tommy Gun.²

2. Who is not allowed to own submachine guns?

You may not possess or own a submachine gun – or any other firearm – in Colorado if you are:

• a convicted felon;
• convicted of any crime carrying more than one year in prison;
• convicted of attempting to commit a felony;
• convicted of a misdemeanor crime of domestic violence;
• subject to a restraining order that prohibits gun possession;
• a fugitive from justice;
• an unlawful user of controlled substances or a drug addict;
• adjudicated a “mental defective” or have been committed to any mental institution;
• an undocumented alien;
• in the U.S. on a non-immigrant visa;
• dishonorably discharged from the Armed Forces; or
• a former U.S. citizen after renouncing your citizenship.³

3. What are the penalties for having a submachine gun?

In Colorado, possessing a “dangerous weapon” (which includes submachine guns) without a valid NFA tax stamp is a class 5 felony. The punishment is:

• 1 to 3 years in Colorado State Prison (with two years of mandatory parole), and/or
• $1,000 to $100,000 in fines.

But a subsequent violation of possessing a dangerous weapon without a valid NFA tax stamp is a class 4 felony in Colorado. The penalty increases to:

• 2 to 6 years in prison (with 3 years mandatory parole), and/or
• $2,000 to $500,000 in fines.⁴

Note that it is a class 5 felony in Colorado for people to possess firearms (including submachine guns) if they have a prior conviction for domestic violence or a serious felony crime. Penalties for POWPO (Possession Of Weapon by a Previous Offender) include:

• 1 to 3 years in prison (with two years of mandatory parole), and/or
• $1,000 to $100,000 in fines.⁵

It is a Colorado felony to possess a submachine gun (unless you have an NFA tax stamp).

4. What other weapons require an NFA stamp?

In Colorado, you must obtain a valid NFA stamp in order to lawfully possess:

1. A machine gun;
2. A silencer (suppressor);
3. A shotgun with a barrel(s) of less than 18 inches long;
4. A rifle having a barrel(s) of less than 16 inches long;
5. A weapon made from a shotgun if such weapon as modified has an overall length of less than 26 inches or a barrel(s) of less than 18 inches long;
6. A weapon made from a rifle if such weapon as modified has an overall length of less than 26 inches or a barrel(s) of less than 16 inches long;
7. Any other weapon, as defined in 26 U.S.C. 5845 subsection (e); and
8. A destructive device.⁶

Legal References