I would never start a baby in a mechanical hackemore; there can be too much confusion because they were not designe for individual pressure like a snaffle bit is. They can get confused by the chinstrap pressure, as well as the extra pressure on their poll, and nose...alittle too overwhelming for a baby in my opinion.
If you want to start out bitless, go with a rope halter, as you can give individual rein pressure, and not confuse him, especially if you have worked with bending to each side prior to ever getting on; it's a good idea to do that anyway as then you know you have your 'power steering' in place. I start out all of my babies in a rope halter, and I like the results. It's extremely important to do your ground work though, first, otherwise you might not like the results of anything you try.
Depending on what you show in, you won't be allowed to use a mechanical hackemore in the showring (pleasure, trail, equitation, etc); gaming, you can can generally show in anything.
If you are talking about a bosal hackemore, this is usually a transition from snaffle, when he already knows rein cues, because even this can be a little more confusing to a horse, because one rein cues aren't as easily deciphered, especially right away in the beginning. Now if you work with him on the ground with the bosal prior to getting on him, teaching him, especially, to yield to your rein cues, like you would when you're on him, then this would be acceptable to start him in.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."
Last edited by mom2pride; 01-10-2010 at 03:06 AM.