In a war, guns are about as common as beer in a bar. And one beer is all it takes to put lightweight Radar over the hill. His drunken escapade in this episode is one of the funniest M*A*S*H moments.
A wounded colonel is brought to the 4077th, and his specially designed 6-shooter gun is placed in a gun safe under Radar's responsibility. However, the gun goes missing, and the colonel believes poor Radar is the thief. When Radar learns what could happen to him if the gun doesn't come up, he turns to alcohol for comfort, and Hawkeye & BJ investigate, so Radar doesn't end up in the stockade.
Any episode that focuses on Radar is always bound to be a fun one. This episode is no exception. Radar gets to experience intoxication and goes on a drunken rant to the colonel who's gun he's accused of stealing from.
Is this episode an anti-gun one? Maybe. It's a real shot in the dark, so to speak.