What would you do if your Sergeant didn't know how to load a magazine?

While I do understand your frustration, I think you're being too harsh. Rank should have nothing to do, you're either trained or you're not, it's not a rank thing. Also, understand that some soldiers rarely fire their weapons, MOSs such as human resources, fuelers, commo, cooks, how often do they get to shoot in s reserve unit? In my three deployments, I saw negligent discharges, and guess what, they were all LTCs. Everyone can have a bad day. Make in the spot corrections and get the task done. Thank you.

And a Combat Patch to boot... AHHHHHHHHH

Not defending this by any means, but I can say it has been years as a reserve Soldier, since I have ever loaded a magazine. During the peak of the war efforts, we were stuck with virtual bullets and virtual qualification. Other times, we are handed pre-loaded magazines. I bet that Soldier in the video has not loaded a magazine since BCT, if they even then.

The Specialist professional as he could be....by videoing the encounter and posting it.

So the unit only has one magazine?

Counseling statement and immediate remedial training!

I'd start with going to my CO. I'm not sure if the next level of the Chain of Command would be available to me but I would most definitely look into it. I can't imagine being in a combat situation with anyone who couldn't load a magazine. It's a simple task and you'd have to have some mental deficiency not to be able to figure it out let alone accomplish it. It makes me wonder if they have done away with the tests that showed whether or not you had the basic IQ to be in the military.

First of all I would pull her off of the line and take her back to the rear for some retraining. I then would be asking why she doesn't know a basic soldier task. I don't understand how she would have a combat patch without knowing this. In every unit I have ever served there was always a train-up period prior to deployment. I didn't see the video so I'm not sure what it was that she was having problems with. I know in certain MOSs the soldiers go through initial training and then go to a unit that just checks the boxes for training. She may have never had to load a mag for herself. She could be in a unit where the armorer pre-loads magazines for range training. I also know that there are soldiers that have never loaded a magazine using the speed load strips.
As far as the combat patch she may just be wearing it because her unit is wearing it, not because she earned it.
Way back in "88 (the year of the Olympics) when I was in Korea my unit set up a mini combat training course for the rear area troops (clerks, medics and cooks) I'm an MP. I was really surprised at some of the basic skills that were lacking in these troops. Many of them went through basic and once they got to their units were nothing more than civilians wearing a uniform.

Believe it or not I've seen worse.

Has to be fake, has to be,I hope its fake...Unfortunately it could be authentic.

I would pull the sgt aside and quietly show the person how to load it and give them full instructions and make them practice it till they got it.

I'm not army/marine where weapons are used a lot....don't know much about job descriptions, but does everyone in the Army learn and practice shooting? Is it required for all jobs...even desk jockeys or cooks? I don't know, this is why I'm asking....

I was Air Force...not a soldier....was never taught in Basic training or after how to shoot, although I did have to shoot and qualify for the M16....good thing I learned before joining.