You can open carry a long gun in Texas, provided that it is unloaded.
The New Black Panthers, or maybe it was Quanell X’s group, protested at an execution a few years back. They marched in formation all carrying AR243’s on their shoulders. It was legal since they were all unloaded.
There are *no* TX laws regarding long guns, except that they conform the the NFA.
That means concealed, unconcealed, loaded, unloaded. Any lawman that claims otherwise is blowing smoke.
They can only be banned from schools, racetracks, courthouses, the secure area of airports, and (on election days) polling locations.