Generally speaking, Texas law allows people to transport a handgun in their vehicle or in a vehicle "under the person's control" as long as they are otherwise allowed to possess a firearm. Texas Penal Code Section 46.02 creates an offense for the unlawful carrying of handguns and in subsection (a)(2)(b), makes an exception to unlawful carry for those who are:
(B) inside of or directly en route to a motor vehicle or watercraft that is owned by the person or under the person's control.
Prior to September 1st, 2021, only those with a Texas License to Carry (LTC) were permitted to keep a handgun in "plain view" within the vehicle. However, House Bill 1927 eliminated this requirement. After September 1st, 2021, Texans who do not have an LTC but are otherwise eligible to possess a firearm can keep a handgun in "plain view" in their vehicle, provided that it is kept in a holster:
(a-1) A person commits an offense if the person intentionally, knowingly, or recklessly carries on or about his or her person a handgun in a motor vehicle or watercraft that is owned by the person or under the person's control at any time in which: (1) the handgun is in plain view, unless the person is 21 years of age or older or is licensed to carry a handgun under Subchapter H, Chapter 411, Government Code, and the handgun is carried in a holster;
We have not found any Texas laws that restrict transporting a rifle or other long gun in a motor vehicle or watercraft. We have also not been able to locate a law that would dictate if a long gun can be "in plain view" in the vehicle.
Texas law does not say where a gun should be stored when it is in a car, or whether it should be unloaded. It is important to keep in mind that other laws may prevent one from carrying a firearm at any time, or may restrict the location where firearms can be carried. For example, see Section 46.04 of the Penal Code, Unlawful Possession of Firearm.