Most mechanical modifications of internal parts are allowed in Texas. But be careful with binary triggers, and definitely stay away from auto sears. While binary triggers are not illegal as of right now, some law enforcement agencies view them as machinegun parts. Machinegun parts, auto sears, and other automatic weapon components are illegal unless part of a narrow exception for machineguns manufactured prior to 1986 and registered with the ATF.
Are there any accessories that I cannot use? If you want to install night sights or a handgrip with a built-in laser, go right ahead! But there are a few common accessories that can get you into trouble. Recent justice department regulations have banned bump stocks, making them illegal to possess or own. Even if it is not installed on a firearm, merely possessing a bump stock is illegal, and it must be destroyed according to ATF standards.
Also highly regulated: suppressors. Suppressors or silencers are not banned outright, but you must register them with the federal government (with ATF form 1 or form 4) and pay a $200 tax to legally own one. If someone asks you to buy their suppressor without the proper paperwork, you should give them the silent treatment.
Finally, vertical foregrips are not allowed on handguns. With the growing popularity of the AR pistol outfitted with a pistol brace, many people ask about vertical foregrips. Attaching one of these to any pistol transforms the once-legal pistol into an AOW. To legally add this accessory, you would have to apply with the federal government to “make and register” a firearm and pay a tax.
As you can see, there are plenty of gun customizations that can get you into trouble. If you plan to make some changes to your favorite firearm and you’re unsure of the legality, call Texas LawShield and ask to speak to your Independent Program Attorney.