I participated in an open-carry even this weekend in Mansfield, TX and last weekend in Arlington, TX. There were about 40 of us. It was quite an interesting experience. I carried my Ruger itac, its a tactical version of the Ruger 10-22 that just looks more like an "assault rifle." Obviously, having lived in Texas my whole life, open carry of any firearm is an odd sight to see. I've known for a while that its legal to carry around my rifle in public, but I've never been brave enough to try it. But when there are 40-some-odd other people doing it with me, I know I'm less likely to be harassed by police. In both cases the police did come out and sort of babysit us and follow us around. I asked the Arlington officer why he was there and his answer was humorous. He said, "We're here for your protection." I replied, "There are over 40 of us walking around with AR-15 rifles, who do we need protection from?" He had no answer to that question.
Some interesting things I noticed. First of all, the public response in both cities has been overwhelmingly positive. There was a constant stream of honking cars. Everyone honking was either waiving at us or giving us a thumbs-up. Some people walked up to us and thanked us for what we were doing. I never heard a single negative comment.
We also have gone into several establishments to eat or buy beverages. We've been in a 7/11, a Chevron station, SmashBurger, and Freebirds. The only negative reaction I have seen was in SmashBurger. One guy was eating with his young daughter and after 30 of us piled into the place with our rifles, he got up and said semi-loudly to his daughter, "let's go eat somewhere else.."
The police in Mansfield were even nicer and they flat out told us they supported our movement and thanked us for being orderly and friendly and for carrying with empty chambers (even though that is not required). They also told us the called the 911 dispatch and told them what to do if anyone called 911 about our activities, basically to inform the public that we weren't breaking any laws and that the police were aware of it.
I've been very tempted to go out in public by myself with my rifle, but I fear I'll get singled out if I'm not with the group. The other issue is that I've done some experimenting and even if the rifle is carried with a round in the chamber, it takes 3 times longer to bring it to bear than a pistol due to its location on my back. So it isn't really that good of a defensive tool, although it may definitely serve as a deterrent.
here are some photos.. Sorry I'm not in any of them since I was the one taking the photos.