As evidenced in the "Grillz" shootout, if the proprieter wants to WIN any potential gunfight in his establishment, he'll just keep a RIFLE handy.
In a gunfight, winning is the only thing.
"If you think there might be a gunfight, the best option is to be somewhere else..... if that's not an option, bring a gun, preferably a big, long gun, and all your friends and aquaintances with their big, long guns....."