You are more correct than you know. Open carry of long guns is not prohibited by State law, but Texas does not have preemption to prevent cities and towns from prohibiting open carry of long guns.
You do not see long guns carried openly for that reason, I believe. No one can know when they cross an invisible jurisdictional line if they have broken the law and may end up in jail.
It ammounts to a defacto ban on the open carry of long guns in most locations.
Yeah. We had a similar situation here in Va till we finally got complete preemption. OC was never illegal, but various cities banned it. And there was no perfect list of which ones.
Thankfully we have VCDL. So that problem went away. A few cities acted like dorks and tried to push the issue. They were visited en masse by VCDL during their council meetings and had amazing policy conversions. A few others got cute and arrested folks for OC. They got the ever popular visit plus a lawsuit.
Texas does have pre-emption on ANY firearms law. That’s why SA will not prosecute you for their law - they don’t want it getting into the court system and getting shot down.
Houston tried it with their gun show ordinances and lost big - tens of millions of dollars and both the state and Feds were annoyed at them.