No, it isn’t.
Within the bounds of naval terminology, a “rifle” (shoulder-fired small arm with a rifled barrel) is NOT a “gun.” That’s the whole point of the ditty.
I’m not sure if you’re referring to the Full Metal Jacket scene or the Family Guy parody, but with respect to the former, the point of the scene is definitely NOT to make “military types in Vietnam look like horny idiots firing their “guns” everywhere they could.”
The point of the ditty was to forcefully imprint a particular bit of terminology into the recruits’ heads. The ditty was likely some (relatively mild) humiliating punishment after one or more recruits used the wrong terminology even after being taught the correct terminology. For the recruits, there was nothing fun about it. They were being forced to sing it.
ETA: with respect to the Family Guy scene, the use of a shotgun instead of a rifle does make a difference, because a shotgun is not a rifle, and the whole point of the original scene was to emphasize the importance of using correct terminology. And that, I presume, was the OP’s whole point.
Was that Kubrick’s intention when including the scene, though? Actual marines may have done that but did he put the scene in just so that people would that it’s important to distinguish one from the other, or just to make the Marines look ridiculous?
Also, I still don’t get why it’s so awful to call it a gun and not a rifle. Another reason why I’ll never be a Marine, I guess.
I think folks get confused by the part where the recruits compare their dicks to guns. The crotch grabbing part is incidental…it was only put there because these ditties tended to be a bit ribald traditionally. The real point, as folks keep saying, is the fact that one should never EVER call their rifle a gun. Call your dick a gun all you want though, presumably.
~ Nzinga, who has never been in the military but who loves Full Metal Jacket.
I think it was to underline the ironic juxtaposition of precision and profanity. After all, the whole movie was about the murderous absurdity of war.
I missed the edit window, but Freudian, I just want to say that I can’t help but to picture you as Private Benjamin as you blink wide eyed at a Drill Sargent and say, “I don’t see the big deal about calling it a gun instead of a rifle”. I get the feeling they are pretty anal about these kinds of things.
True. I’ve only actually seen that one bit, and I had no idea that Marines actually did that. Consider my ignorance fought on that front. It definitely did make me think of the similarly ridiculous stuff in “Dr. Strangelove” – no fighting in the war room and all that. While the literal meaning probably was that the characters shouldn’t be fighting in that room, I doubt that was the only reason Kubrick put it in, just as he probably wasn’t just trying to teach the audience members about how to distinguish a rifle from a gun in Full Metal Jacket.
ETA: Shucks, Nzinga. I always saw myself more as Goldie Hawn’s uppity bitch who needed to be taken down a peg or two in “Overboard.” 
Which is exactly the same thing as saying that the navy and marines require a level of specificity that is unnecessary outside that context. The word “wrong” is a red herring.
Sure, I can see you as a stuck up but redeemable Joanna Stayton. (another fave of mine and I heard that there is supposed to be a remake of Overboard with Jennifer Lopez taking over the Goldie Hawn role and I will personally claw Mz. Lopez’s eyeballs out if she lays a single Lee PressOn™ upon that awesome character.)
I’ve heard that, too, and it fills my heart with more dread than the thought of being forced Clockwork Orange style to watch Seth Rogen lend his voice to a CGI version of ALF.
If I ever get business cards, I vow to put “stuck up but redeemable” on them.
Because when your platoon is under heavy fire, miscommunications are very, very bad.
This doesn’t answer the question. You could call it a “miscommunication” if you wanted to be specific.
HOW is it bad? What happens? Let’s say you and me are under heavy fire. What is an example of a miscommunication of “gun v. rifle” that ends horribly?
So if in the heat of the moment someone tells you to fire your gun, not your rifle, what’s the worst that could happen? Besides a soggy pair of drawers?
Just out of curiosity: how about smaller “guns”, i.e. pistols?
“Munch, it looks like we’ve got company! Hand me those bullets for my gun! Hurry! MOVE, MOVE, MOVE!!!..Goddammit all to hell, these don’t fit! They aren’t going in! WTF? Munch! These aren’t the damn right bullets! I need the bullets that fit my Rif…I’M HIT! I’VE BEEN HIT!!!”
Aren’t there different bullets for different types of rifles, though? By that rationale, shouldn’t you be saying the exact name of your rifle instead of just “rifle”?
Narrowing it down to the right category is a start, I guess.
*‘Get the gun over there’ *would probably be intended to refer to the squad’s light machine gun. Getting a rifle over there would not meet the speaker’s requirements.
“We’re under gunfire here. Please send reinforcements.”
“We’re under rifle-fire here. Please send reinforcements.”
The reinforcements sent might be different, and thus things might end poorly.
If I’m in the field, I don’t think there’s going to be anyone near me under the mistaken assumption that I have a battleship gun. It’s certainly going to be miscommunication over the radio - I just don’t know what that is.
As for the FMJ scene - there’s a lot going on. It’s not JUST about telling marines there’s a difference between guns and rifles. It’s also saying you don’t play with your rifle. It’s also bonding you with your weapon (as is the “this is my weapon, there are others like it…etc.” scene). It’s also simply trying to humiliate you.