Under the deadly force laws in Texas, you would be justified in shooting them. You do not have to outrun them, catch them and take a chance in a scuffle of them taking your guns from you and using them on you. Other States may be different.
Under Texas law, you MIGHT be justified in shooting, since Texas allows the use of deadly force to protect property in very limited circumstances. However, the Texas law allowing this has many qualifiers in it, one of which is that you reasonably believe the property cannot be recovered by any other means. Also under Texas law, the grand jury is going to be the one deciding whether you met those qualifiers.
In legal terms, what you describe may be legal depending on your state law. It is almost never a good idea tactically, whether legal or not.