Continuity mistake: In the first episodes, Col. Blake's wife is named Mildred, later her name is changed to Lorraine. (In case of confusion, when Col. Potter came to the 4077th, his wife was also named Mildred, but that's not relevant).
Continuity mistake: In the first season of M*A*S*H, Hawkeye mentions that his father lives in Vermont, in the later seasons his father lives in Crab Apple Cove, Maine and has never left there in 30 years.
Continuity mistake: At one time, Col. Potter talks about how his daughter is an only child. In a different episode, he mentions that his son's wife is having a baby.
Continuity mistake: There are two sets of the 4077 compound - the outside Fox Ranch set located at Malibu Creek State Park, and the second set inside the studio's Stage 9. The layout of both sets are quite different - Studio 9's set was vastly smaller than the Ranch set, so things such as the proximity of the Swamp to the mess tent are different between the shots filmed at the Ranch and shots filmed at Studio 9, when seen within the very same episodes.
Continuity mistake: In the pilot episode it says the year is 1950. In the episode "Radar's Report" in season 2 Radar says it's 1951, yet in the episode "A War for All Seasons" in season 9 we are told at the beginning of the episode they are going from 1950 to 1951.
Continuity mistake: In an early episode Hawkeye receives a sweater knitted by his sister. Subsequently in the show he has always been an only child.
Continuity mistake: In the episode "Change of Command", Potter asks Mulcahy if he "can do Methodist". In the episode "Period of Adjustment", Potter asks Mulcahy "You wouldn't lie to a Presbyterian, would you?" Just what denomination *is* Potter?
Continuity mistake: In the episode "It Happened One Night", Klinger has B Positive blood type. In the episode "C*A*V*E*", Klinger has AB Negative blood type. Blood types *never* change.
Continuity mistake: In early episodes, Margaret's father was dead. Later, he was alive and visited the camp. Also, in a early episode, Hawkeye writing to his father, tells him to send his love to his mother. Later, he tells Winchester his mother died when he was a child.
Continuity mistake: In one episode, Frank's middle initial is M, then later it's D. His full name was Franklin Delano Marion Burns.
Continuity mistake: In any scenes in the CO's office, look at the windows - they're sometimes opaque, sometimes clear. Also the windows in the OR. Usually semi-opaque, once, they were totally opaque, and made of a thick plastic. This was because it was very cold outside, and Hawkeye used a scalpel to cut them open to let in cooler air.
Answer: Even an Army field hospital would have SOME weapons for self-defense if the enemy attacked. What's meant is that it's not a combat outfit, and therefore wouldn't have enough weapons to actually attack anyone. (It's also mentioned a few times that the Officer of the Watch is supposed to carry a pistol at all times, but Hawkeye refuses to do it when he's in charge and Colonels Blake and Potter don't enforce the rule).
Captain Defenestrator