Welcome, and you might want to post this in the MI sub-forum. In WA you can go into a restaurant that serves alcohol, just not in the 21 and over only area. No federal law about not carrying in an FFL. I carry in Cabelas, and all my favorite gun shops. That said, any private business can have a "no gun" rule. In some states the signs carry the weight of law, other states like WA you can post all the signs you want and they mean nothing legally. Again, check the MI forum my knowledge is based on WA laws.