After reading Metaldams's and Shemp Diesel's posts I had a look at the reviews of this short on its page in this site: clearly this short evokes extreme reactions. But I don't share them: I think that, while this short is, at least for a lot of viewers (with me among them), unpleasant to watch in a way and to a degree that no other is, it is not among the worst of the lot: I reserve that honor for the shorts with Joe Besser. While fundamentally badly conceived, Half-Shot Shooters does not have the sustained corniness and contempt for comedic standards that the last shorts have, and it has some pretty good stoogery along the way. In general, as long as Sergeant McGillicuddy is out of the scene (more on that qualification in a moment), the writing and execution are up to the Stooge par.
Setting aside the objections that could be raised against using the monstrous mass slaughter of the Great War (as it was called at that time) as a scene of comedy--arguably no worse than when the Stooges do the same thing with the American Civil War--and, again, setting aside what happens when the Sergeant is on the scene, the opening business with the Stooges trying to sleep and hitting each other on the head with frying pans and rifle butts is not badly done. We get, as has been noted, the first appearance of the Stooges' great cubical nemesis Vernon Dent, who displays his characteristic volatility, apologizing for losing his temper when he sees a way of getting vengeance on the Stooges without violence. (My favorite line in this confrontation is Moe's response to the slap in the face that Dent gives him: "Oh, a face-slapper, eh?" Another instance of the Stooge genre of concise verbal encapsulation of the obvious!) The business with firing the cannon into a series of erroneous targets is funny, I think, as long as we presume that there are no human beings in those targets; though admittedly it is hard to think that of the ship that gets hit (especially if we think of that explosion as a foreshadowing of the attack on Pearl Harbor). There are a few funny bits along the way, such as the chanting of "Gun range okay!" in harmony and Moe's quip, "I don't know where that one went, but I hope it didn't hit the pool room!"
Now to Sergeant McGillicuddy. If anyone finds anything funny in his acts of brutality, I can't share that sentiment, for the reasons given by Metaldams: Stooge violence is funny only because it is utterly unrealistic and has no serious consequences (e.g., a sledge hammer hitting a Stooge on the head with a clanging noise and causing only a momentary stupefaction to the victim while the iron head of the hammer itself is flattened), while Sergeant McGillicuddy inflicts pain, bruises, sprains, and possible eardrum damage in a comparatively realistic fashion. Acts like that don't belong in slapstick comedy, unless perhaps their perpetrator is being set up for a huge, comically exaggerated comeuppance, which doesn't happen here. The best that we get (and it is pretty good in its way: it is the only bit involving the Sergeant that does make me laugh) is the business in which the Sergeant, provoked by the refusal of the Stooges to relinquish their tomatoes, pitches a tomato at them and hits a general, landing him in cuspidor-cleaning duty. This is funny because, in contrast to the business in which the Stooges retaliate against him after they are released from military service, brutality is not answered with equally arbitrary brutality but rather brings about its own punishment by its own arrogance.
The fact that brutality triumphs over the Stooges at the end of the short, when the Sergeant kills them with the cannon, is in its way consistent with the basic conception of the short; but that conception is itself at odds with the nature of the comedy of the Stooges.