The Quarter Horse Journal had a long article with several x-ray pictures of bits hanging in horse's mouths and some with reins tight, showing how they moved in there.
It was interesting and one of the more salient parts of that study is that full cheek snaffles, when attached by the keeper, were poking horses in the palate, when loose they could rotated and lay along the tongue.
That I had figured long ago, from the way horses work in them.
Standard first classes for beginer riders included going over the horse, the grooming of the horse and tacking up.
One way we explained to the students how a bit works in a horse's mouth was to have them hold the bridle in the middle with one hand and the bit, palm down, in the other hand.
Then, from behind, we guided the horse by the reins and the student would then understand how the bit moved and how sensitive a horse could be to the slightest signals.
We used a plain snaffle and a curb bit to demonstrate.
I have since used that same for the 4H kids.
I think having that understanding made riders be much more aware and so lighter with their hands, they go from pulling on them, to trying to communicate, with intent, with them.
When it comes to any new bit, I still "try" it on my hand first and evaluate how they hang, how they move and what the horse may get out of them.
Loose ring snaffles are some of the more "noisy" bits and we can see that in our hands very well.
That is one reason it is standard to use a more steady D ring snaffle for most colt starting in English riding, where we have steady contact and need a more firm, steady signal.
however, what i am looking into is how different bits actually work and affect the mouth.
looking at the kk ultra/kk conrad/regular french link and trying to understand how they affect the tongue/bars/palette, was what got me thinking.
the mareketing pics of the kk ultra that are used never show the bit how it actually sits in the mouth..... so i am trying to understand how- say a kk ultra can be horse friendly, (come to find out it isnt about the tongue it is about the roof of the mouth in the kk ultra )
all bits affect the mouth differently, and using it on our hands/shins is not he same...
in the end i am trying to make an intelligent choice of bit for my horse - and not spend a gamillion in the process.