You might be pleasantly surprised by the effects of a mechanical hackamore. It takes the PTSD with some long-standing abuse of his mouth or his profound lack of education out of the equation. Riding in a hackamore, however, is all about contrast. You need to have a loop in the reins unless you mean to speak to the horse.
Otherwise, you need a thin, unstable bit, some spurs and someone with a great deal of education and a clear, intelligent training philosophy.
Again, what you are teaching here is the contrast between neutral contact and contact that means something. Whenever you touch the bit, initially one just one side, he should step under with that hind leg, soften his jaw and even turn his head in that direction. You need the leg and perhaps the spur because it's all bogus if the horse doesn't engage his hind end. Without the hind end, he'll lean on the bit again.
If this horse's job is to be a safe, predictable and calm husband horse and he is generally doing that job well, reschooling him this way wouldn't be my very first choice. Sadly, part of what you'll be doing to the horse is telling him that his way of resting on the bit is *not okay*. And chances are that you'll scare ("impress") him a bit. That's fine initially, but then his competent rider needs to re-establish that new set of rules in which he gets away from the bit if he gives to it. Do this well and with intention or don't do it at all.
I hope you guys can try out a mechanical hackamore and get the job done that way to everyone's satisfaction.
i personnally wouldnt put a hackamore of any kind in unexpereinced hands as a hackamore works on the bridge of the nose and inexpreince of using them can result in disaster of either a broken nose and chin or both
bits are only as strong as the hands that use them which is a true quotation
but if one has a hard mouth which is causing sores to a horse
then one must look at why and mostly its rider error in the horses education
if i had a horse that pulled and was hard mouthed as you i pressume are saying then i would take the horse right back to basics and re school him/her and more than likely wouldn't end up being a 1st horse more of a second horse for an experinced rider who had the knowledge to carry on his/her expectations and who could also carry on with the the education the horse needed to be able to extend his power and use it
the rider on the other hand would be re educated and advised a mount that is more suitable to thier riding skill which would as a novice rider
most people will balme the horse for xyz -------- when in truth its the rider that needs looking at as some cant take being told its them at fualt
horses at the end of the day only do what people tell them good or bad your the rider and your in control of your horse so good or bad it learns by you
if the hrose has learnt to be a hard in the mouth and you end up pulling it round rather than asking it go forwards then your in a no win battle as the horse will always win as hes far strong than you
the point here is to ask the horse and not dicatate by pulling it here and there its not nice for the horse and in fact when pulling on the riens to right left and what ever the bit is moving harshly in his mouth which will make briuses inside and cuts and sores outside in his defence when ridden like that his only option
is tank and be a git to run away from the pain caused
horses have 2 fears factors 1st is to flee 2nd is to advade be that ridden or driven or handled
if one rides as in pulling the horse to get to xyz- then the horses fear factors come into play and its both of them in a horses mind which come to his defence
1st is to flee away from pain cause by the hands that riding the horse and the 2nd is to advade the bit which is causing pain in his mouth
so point is wise up and look at what your doing to make your horse act the way he does
for might need more lesson in the way your riding and the horse needs time of to heal his mouth and neck mussles and during this time of ridden work put him in a cavasson and lunge better if one can do long reining with a proper trainer which you can go onto any major web site to find riding clubs and societies to find one near you
and start the horse off via voice commands learning simple commands which will make the horse more relaxed and understand what his job is, and then progress adding the bridle once his mouth has healed competely which can be upto 2mouths if he has bruising inside - can tell as there mouth goes black with scaring
and the big thing is to take it on broad that you need to look at you and accept that
excuse me while i put it in big word to make you listen
UNDERSTAND WHAT YOU DO IN THE WAY YOU RIDE EFFECTS YOUR HORSES WAY OF GOING WHAT NEEDS CHANGING BIG TIME IS YOURSELF