Example, a friend and I were outside a Starbucks, driinking coffee and had 2 AR lowers on the table, no ammo, no uppers. Someone called it in, 3 cruisers responded. Legal means nothing when a "man with a gun" is called in. Discretion is best. Good thing was the officer that approached us was knowledgeable, friendly and professional. After checking our IDs and we informed him we had CHLs and were armed, he just asked us to put the lowers in our vehicles.
Not surprising in Austin, which is where the OP is from as well; but your comment "Legal means nothing when a 'man with a gun' is called in" is spot on. No matter what, there will be a quick and severe response to any 911 call that has the word 'gun' in it!
The way I understand the law, you can carry a loaded long gun anywhere a CHL holder can carry concealed.
Unlike SA, I don't see anything that prohibits it in Austin ordinances...