Colin got me a bosal for my birthday - I took my own sweet time in deciding when to order it, but I finally did. I worked with Bill Black on custom sizing for Mac because his head is so big. It came in the mail last week! I tried it on Mac and I'm hoping the sizing is right.
Here's a picture from the side so you can see the space between his chin/jawbones and the heel knot.
I went out to buy a horse hair mecate the next day and have practiced tying it a couple times. The weather is supposed to be good tomorrow so will tie the mecate on, put the bosal on, and maybe give it a try just at the walk to see how it feels. I signed up for a hackamore clinic this spring so that should give me some formal instruction on how to get started.
Hopefully more pictures soon!