Transcript for Texas Pro-Gun Crusaders Take Extreme Open Carry Approach

It seems more Americans are packing heat in public. And now members of a new group are bringing their guns with them everywhere, not only to rallies, but to stores, even family dinner. They're certainly making waves with this approach to bearing arms, but are their civil liberties encroaching on public safety? Reporter: Just imagine you're sitting down to dinner with your family at a restaurant, when in walks a handful of men, armed with assault rifles. Are you frightened? 911, what is the emergency? I seen four white men walking towards the jack in the box with assault rifle. Reporter: Angry. If a bad guy comes, there's a lot of good guys here to protect me. Reporter: Surrounding a group of gun carrying activists, flexing their legal right to bear arms. This is probably the safest corner in San Antonio right now. Reporter: They call themselves open carry texans. Their enthusiasm for packing heat in public has led national chains ask customers to love their weapons at home. But what they're doing is legal. Gun control activists detest it. You're ammo sexuals. Reporter: Far more than a punchline, open carry Texas has become the hype in the sand between those in America who fear guns for violent use and those who fear losing their guns. Everybody say freedom! Freedom! This is sort of my around the house ar-15. Reporter: I've never heard it phrased that way. This is the man behind open carry Texas. Master sergeant C.J. Grisham. A 20-year U.S. Army veteran and father of three. He keeps his own arsenal of assault rifles in his bedroom close et. All my weapons is always loaded. It's just a beating stick if'9"'s not loaded. Reporter: He said one traumatic event was the spark that ignited it. I was arrest ed last year. Reporter: He said he had that rifle to protect them from wild animals. A police officer approached. Some reason why you have this? Because I can. Reporter: Since carrying a rifle is legal in Texas, he believes what happened next is illegal. At that point, he stuck his head to my gun and threw me to the car. Reporter: His son videotaped the arrest. His father later convicted of interfering with police duty. My son had to watch this whole thing. Did Y Reporter: He said he's state battling the demons from tours in Iraq and Afghanistan. The arrest triggered one of the worst episodes of PTSD he's ever endured. I've always been a gun rights advocate, but this turned me into an activist. Reporter: That arrest video took off and a movement was born. The first flag we ever had ordered. Reporter: With a goal to expand open carry rights in Texas. While it's legal to carry so-called long guns like ar-15s, state law prohibits the open carry of hand guns. He wears a plastic pistol every day to symbolize his fight to expand open carry laws. That's the bottom line for you, the right to openly carry a pistol. Right. Once we get that, we won't be walking around with rifles. But we should have that opportunity. Reporter: Nearly every week, dprisham, his wife and often 1 and -- 1 and 16-year-old hit the road. This night he invited us to a rally in San Antonio. Here are people with guns that are not shooting up schools. I realize there are people that have what I call an irrational fear of guns. Reporter: He stressed the fact that he always calls ahead to alert police about his marches. We meet nearly two dozen supporters, men and women, gun lovers of every raise. So often when these events are covered by the media, I may see this gentlemen or that gentleman, but I don't see you there. My house was robbed about four months ago. The police did nothing. Therefore, it's my duty to protect my family. Crime has no color. Reporter: Open carry members waving and passing out flyers. Most motorists are supportive. But some -- what do you think of these guys? They're Nuts. What do you think? Reporter: I'm a journalist. Run away. What did they do? Reporter: Amidst the smiles, there is hardline rhetoric, deep contemperature for those who see the spike in mass murdering as a cause for greater gun control. Instead of standing on the bodies of those dead shoulders as a soap box and trying to reign in gun rights, there's more people killed by hammers and fists than by firearms. Reporter: Actually, the hatest data shows that firearms are responsible for 69% of homicides in America. Clubs and fists, 9%. But the nation's gun debate is far more than statistics. It's emotion, mass murder that cannot be easily explained away, from Aurora to sandy hook. One line of reasoning one might think is someone like yourself who has seen the results of what can happen when a gun is used against another human being, but you might be more inclined than the average person to want to restrict who has access to that kind of power. No, I don't see it that way. I'm sure some people probably do. Reporter: He spoke to us openly about his battle with PTSD, including the memories of the seven people he says he killed in combat. I can picture exactly how that person fell. How that person, you know, limped off or tried to get away. Reporter: For those that would hear that part of your journey and say here's someone that understands better than most the demons that can exist with mental health issues. Going back to my PTSD, regardless of everything I've been Thu and how I felt, I never once reached for a gun. The way to deal with a mentally disturbed person with a gun is a sane person with a gun. Reporter: Of course, gun control advocates disagree. Right now open carry Texas is at the center of a massive petition movement led by a group called moms demand action for gun sense in America. There's no background check required. There's no training required. And there's no licensing required. So anyone can be walking around with one of these long guns and they carry them rnld loaded. Reporter: Carolyn is part of the movement pressuring stars like target and Home Depot to ban open carry this their stores. Companies need to provide a safe environment for consumers. Reporter: But Grisham and supporters believe more guns means greater safety, and his movement is growing. Gun owner by gun owner. Anybody want a flag or t-shirt? As long as there are people that don't think law abiding citizens should have guns, this is going to be a struggle that's going to go on forever. Reporter: For "Nightline," Byron pits, in San Antonio. Up next, one minute he's

This transcript has been automatically generated and may not be 100% accurate.