Illegal Gun Modifications in Illinois

Updated on 08/10/2023 / Under

There are a lot of gun enthusiasts who modify guns for creative aesthetics, better performance, and better physical control. There are many modifications that are completely legal, but there are some modifications that aren't. It is important to understand what modifications are legal and which ones aren't. Before modifying your firearm you must first know the local gun laws and regulations on firearms in Illinois and never perform an illegal firearm modification.

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If you have questions related to current gun control laws or are facing criminal charges relating to firearms violations, contact our experienced criminal defense attorneys at Ktenas Law. Contact us today to schedule a free initial consultation!

Illegal Gun Modifications to Avoid

Common illegal modifications that should be avoided include:

  • Cutting a Shotgun Barrel to under the length of 26 inches
  • Rifles with barrels less than 16 inches long or shotguns with barrels less than 18 inches in length
  • Rifles or shotguns with a total length of fewer than 26 inches
  • Converting a semi-auto firearm into a fully auto firearm
  • Converting a firearm to fire .50 caliber

Local regulations may make other modifications illegal as well. It is critical that you know and understand your local firearm laws before modifying a firearm. Illegal modifications can result in jail time, significant fines, and confiscation of the firearm that was modified.

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People often modify their guns by adding parts to them. These can include suppressor devices that reduce the overall volume of the firearm's discharge. Silencers are illegal in the state of Illinois. 

Another modification involves a Glock switch or an auto sear. These devices can turn a semiautomatic rifle or pistol from being a one-shot weapon into an automatic that fires multiple rounds with each pull of the trigger. This technique turns a legally owned semi-automatic firearm into a fully automatic weapon, which is illegal to own in Illinois and under federal laws.

Learn More: How to Beat a Gun Charge

Common legal modifications you can make to a firearm include: 

  • Cosmetic modifications alter or enhance the look of the firearm. While some cosmetic features are for looks or personalization of the firearm, some can also be practical changes
  • Caliber conversion alters the caliber of the original firearm to be either larger or smaller. This is a common alteration for better performance for hunters  
  • Accurizing a firearm will help increase its accuracy. This can be achieved in a number of different ways, such as adding weight for better control during firing or adding sight enhancements. These modifications are common for competitive shooters
  • Conversions of the firearm's operating mechanism can be basic or complex. This type of modification includes converting a handgun to a carbine or rifle or adding a rifled barrel to a shotgun 
  • Sporterizing a firearm converts a military-grade weapon to meet civilian allowances. This is common among sport or competitive shooters 

Before You Build or Modify Your Firearm

It is important to understand the state of Illinois and Federal firearm laws before building or modifying your firearm, as you could create an illegal firearm or render your gun illegal. It is also important for you to know the various laws related to the possession or transfer of weapons by or to prohibited individuals.

If you're facing handgun charges for creating, modifying, or possessing a firearm, make sure to fight them aggressively. You can face serious consequences if convicted.

Gun Control Laws in Illinois

Under Illinois law, the following firearms or accessories are illegal to possess:

  • Machine guns
  • Rifles with a barrel shorter than 16 inches
  • Shotguns with a barrel shorter than 18 inches or any weapon made from a rifle or shotgun and modified with a length less than 26 inches
  • Stun guns or tasers
  • Explosive or metal-piercing bullets
  • Set spring guns
  • Silencers

In addition, you must wait 72 hours between firearm purchase and possession.

Firearm ownership in Illinois is restricted by the following individuals:

  • Convicted felons
  • Narcotic addicts
  • Mental hospital patients released within the last 5 years
  • Mental hospital patients released over 5 years ago, unless they have a Mental Health Certificate 
  • Individuals with intellectual or developmental disabilities
  • Prisoners
  • Individuals under a protection order
  • Anyone convicted of a violent crime involving a firearm within the last 5 years 
  • Convicted domestic abusers
  • Juvenile delinquents who would have faced felony charges if they were tried as adults
  • Illegal aliens
  • Individuals who have been dishonorably discharged from the U.S. Armed Forces
what to expect

Open carry is not allowed in Illinois. Eligibility for a Concealed Carry License Different eligibility rules apply for residents and non-residents. Residents must meet the following criteria:

  • Be 21 years old
  • Have a valid FOID card
  • Have not been convicted or found guilty of a violent crime in the past 5 years
  • Have not been convicted or found guilty of more than 1 DUI in the past 5 years
  • Not be subject to any pending warrants that would lead to a suspension of their FOID
  • Not have been in a residential or court-ordered substance rehabilitation facility within the past 5 years
  • Be free of objections by law enforcement
  • Complete mandated firearm training

Non-residents are required to meet both the FOID and Concealed Carry License requirements and pay a fee.

Related Content: Gun Lawyer in Chicago

Penalties for Possessing an Illegal Firearm

If you are found guilty of violating Illinois firearm laws, you can face jail time in addition to a fine. Penalties are issued per firearm as follows:

  • First offense - Class A misdemeanor punishable by up to 1 year in prison and a fine of up to $2,500
  • Subsequent offenses - Class 3 felony punishable by up to 5 years in prison

Illegal firearm possession can result in Class 2, 3, or 4 felonies depending on the circumstances and type of the firearm. In certain instances, such as possession of a firearm by a prisoner or possession of a loaded machine gun, the possession charge can escalate to a Class X felony which carries penalties of up to 50 years in prison. 

It is illegal to possess a firearm on or near elementary school or secondary school grounds in Illinois. Violations can result in a Class 2 felony, which is punishable by up to 7 years in prison.

Learn More: Unlawful Use of a Weapon in Illinois

What to Do if You Are Caught With an Illegal Gun Modification

Both state and federal gun control laws can be complicated and are constantly changing. If you are facing criminal gun charges or have any questions relating to current gun control laws, you should find a Chicago criminal defense attorney with experience in Illinois gun laws to speak to. Contact an experienced criminal defense attorney at Ktenas Law to schedule a free initial consultation.