This is not advancing the cause of second amendment rights. Is anyone that is on the fence about your gun rights going to react positively to this? No. All it does is make you look like an asshole. Mission accomplished on that front.
One of the nice things about living in the USA is that you don't need to bring a rifle to lunch, and if you do then you can leave it in your truck. If you want to bring your rifle to the mall then move to Somalia.
The idiots pictured look exactly like the type of losers you would expect to see bring a rifle to the mall in the name of 'gun rights'. If you want to represent for then it is important to at least appear professional to the neutrals. You don't have to put on a tie but you can at least look presentable. Or not. Not's good.