You can’t carry a gun into a bar in the state of Missouri. You also can’t carry a gun into any establishment where the primary item for sale is alcohol. What does that mean if the establishment makes more than 51% of its money from the sale of alcoholic beverages? You can’t bring a gun in there.
Now, if you have a concealed carry permit it is not considered a crime to go into a prohibited establishment, but you can be asked to leave and cited for trespassing if you don’t leave. The other thing that’s important to remember is the charge in Missouri for felony unlawful use of a weapon. If you’re intoxicated and you’re carrying a firearm, you can be charged for felony unlawful use of a weapon. Now, intoxicated means different things to different people. Some people think well if I’m over a .08 blood alcohol concentration, then by law intoxicated. That’s true, but intoxication is actually broader than that. You could be less than a .08 as far as your BAC, or your blood alcohol concentration, is concerned and still be considered intoxicated by a judge or jury. So be careful if you’re going to drink. Don’t drink too much if you’re gonna be carrying a gun, and maybe a good rule of thumb not to drink at all if you’re gonna be carrying your firearm with you and you are out in about the town.