Took off optics so they could learn shooting with irons...plus wanted to reduce the weight. Yes stock was collapsed or in 1st notch position. Balance is definitely key, since they had no issues with the versamax.
I was thinking of getting/building a new upper for this purpose, but wanted to hear out any alternatives or options to also improve my existing AR.
Honestly the rail does make a difference. Going down to something carbine length will not only cut the weight, but shift that weight more rearward.
You could try teaching them a biathlon stance, but, it's not the most stable and they could fall over from the recoil due to their size.
I would purpose build them an upper. Streamlined as possible. 11.5" Barrel, Hogue tube, and maybe a tiny red dot.
I would also wonder if there are other reasons they don't like it that they aren't telling you. Forcing them to learn irons might not be a good route.
Something easy and fun like a red dot might get them more stoked on the gun helping them push past the learning curve.
Start them off learning the fundamentals of holding it and shooting it, then move onto irons later.
Having to overcome too many things at a time could be overwhelming.
From my experience with some new shooters, there is an aspect of psychological fatigue that goes a long with it.
They can perceive the gun as being heavier then it actually is if it's not fun too shoot.
If they are having a fun time and it's easy to shoot, it will give them excitement and a boost of stamina if you will.
That kinda of thing happens with my GF all the time. If shes not into it, it might as well be a cinder block.
2 main things that turn her off is any kind of optics other then a red dot, and if it's too loud.
That makes me wonder what kind of muzzle device you have ?
The AR does not have a lot of recoil impulse, but it is a sharp and snappy impulse, especially on a 16" carbine.
Things like a heavier buffer, and maybe even an adjustable gas block can smooth it out.
Going back to the muzzle, if you have a break and pile concussion on top of that it could be startling to them, cause the blast from the small 223 round can also be quite a bit more loud and snappy then that from larger guns.
Also, what kind of trigger does it have. I would also consider that if you have a typical ~7lb mil-spec, the trigger too might be too heavy for them, further detracting from the fun.
I would also consider, if you're going to get a new upper, one of those 22LR poly receiver dealies.
That's should drop some weight, and also mellow things right down. Throw a tiny red dot on it, and they should have a blast.