In Texas, license to carry (LTC) are pretty common and I have never seen a range with a sign discouraging carry of firearms on property. However a private business is just that, and can do what they want. If a business wants to discourage carrying a firearm on their property its their prerogative, probably not a good idea for a business built on guns but it is what it is. I don't know the laws in that area but in restricting states you can't carry a gun, open or concealed, into a gun store or range without it being cased.