When working with a SM that clearly doesn't know his job, how does a lower enlisted handle this without coming off as insubordinate or etc?

A thousand years ago, I was at Camp Casey, Korea (86-87), and my squad leader (SSG) was functionally illiterate. When he found out I had some college, he made me sit outside his office when doing monthly counseling... "PFC Motyka, how you spell 'Motivation'?" "PFC Motyka, how you spell 'Counsel'?"

On top of this - he couldn't find his ass with both hands if you spotted him nine fingers.

After three months, I couldn't take it any more, and lost it. "Motivation: M-O-D-A-V-A-S-H-U-N," "Counsel: K-O-W-N-S-E-L-L."

Guess what we found out that month? We found out that Top actually picked one platoon each month and read through the counseling statements. My SSG was called in by our Platoon Sergeant (VERY red-faced), and within five minutes, I hear him screaming my name.

Our First Sergeant asked for clarification and I told the truth. "Hey, just have him try to spell 'Platoon'!!" Top gave my SFC a nod and he grabbed me by the shoulder and took me into the (thankfully empty) CO's office and started screaming at me like only a senior NCO and prior Drill Sergeant knows how to do. When he started pushing chairs and knocking crap around, I started to pay attention - and he was all, "AND I'M GONNA BE YELLING AT YOU LIKE THIS BECAUSE IT'S EXPECTED AND YOU'RE GONNA WALK OUT OF HERE AND LOOK LIKE I TORE YOU A NEW ASSHOLE, DO YOU UNDERSTAND?!?!"

I was confused as hell as he kept it up for about fifteen minutes. Top opened the door, and it was like someone just turned off the "Pissed off" switch in my Platoon Sergeant. The SSG was never seen again - relieved for cause and transferred that very day - and our Sergeant got the job as Squad Leader. The matter was never broached again.

Yeah, I don't think that would be allowed any more...

SPC (Join to see), speaking as former 11C, if the problem is leadership skills, then you are probably better off to let it go. Those will be built with time. Remember that working on a mortar is a team effort, and as part of the team then you can try to work with the individual to get his skills straight. If however, he is messing up on live fire FDC plots, or firing the mortar in the wrong direction a few degrees (more than 2-3 degrees) then it is time to talk to the Section/Platoon Sergeant, and let them know what is happening. This is a safety issue that must be addressed before someone is injured or worse. When you address the next higher NCO, be sure to only give the facts. Don't make comments like, "He has no idea what he is doing". Try instead to say something like, "I need to talk to you about a safety issue. I noticed that SGT Smith's plot was over 18 degrees off. We almost (could have) dropped rounds outside the impact zone.", or something to that effect. Don't try to insult the individual in question, try to get him help where he so desperately needs it.

And, be ABSOLUTELY SURE that you know what you are talking about. Regardless of whether you are right or not, don't expect a warm welcome, especially if you are talking about the next higher NCO in your chain of command. But safety is always first priority in any case. Good Luck !!

There are a couple of routes you can take.
1. Probably the most preferred, and best soldier style way you could go, get with an NCO whom you feel comfortable with and that has a good relationship with the person you're talking about and have him/her address the person.
2. If you know this person is reasonable, and will listen to you, then have an "offline" discussion with them. Just be sure you don't make it appear that you are challenging them or questioning their position/authority/leadership. Make it cordial and understanding as to why you're addressing them with the matter at hand. If they're a good Soldier/NCO, then they shouldn't mind that you are looking to improve them as a soldier/leader by helping them and pointing some stuff out.