I received an e-mail from Abrahim who asked about fitting a Bosal. " Dear Sir, I am wondering if you could give me some information when using a Hackamore on a horse how the nose band should be (placed) and is it supposed to be a tight fit. "
That's a great question Abrahim, but I'm going to address it as 1 - fit of the nose band (Bosal) and 2 - placement of the Bosal, as I think it's two different things. For instance on fit, the Bosal has to have some movement in it, but not much. If you have a Bosal that is only making contact on the top of the horse's nose with Bosal's nose buttons, then all the weight and pressure of that Bosal is impacting at this location.
Consider a Bosal that forms to the horse's nose and upper jaw - this is likely more comfortable for the horse to carry. This is going to be more oval shaped than round shaped.
Most of the movement of the Bosal is between the horse's jaw and the heel knot where your mecate is tied to. You should have 2 or 3 fingers width here so that the Bosal heel knot can move backwards then drop forward back into place when released. The picture at left shows two fingers of space between the heel knot and tied on mecate when the Bosal is in a relaxed or forward position. One less wrap of the mecate or an extra wrap of the mecate above the heel knot can add to or reduce this space.
And placement is important, as if you have the Bosal too low on the nose it can hurt the softer nose cartilage just ahead of the nostrils. A rough placement for the Bosal is to look for the horse's nose bone as it starts to taper towards the nostrils. Find where the nose bone is not longer visible and place the Bosal up a couple, maybe three, finger widths to start. I'd be concerned with fitting the Bosal lower than this. The picture at left shows two finger widths above the spot where the nose bone tapers to a "V".
The Bosal's fit, or what you are asking about as "tightness", is that the nose band portion of the Bosal's nose button puts pressure on nerves on the top and sides of the horse's nose. The Bosal should not have to be "opened" or pulled apart as it is placed onto the horse. This would be in effect squeezing the nose.
The Bosal can't be round or loose, or otherwise have a sloppy fit on the horse's nose either. A loose fitting Bosal will put too much pressure on the top of the nose and make signaling harder for lateral work. The picture at right shows a pretty decent fit as I just slide the bosal onto the horse's nose. I was scratching Junior behind his ear so he would stand still for a photo.
I use a block to shape a Bosal, see the picture at right. I'll coat the rawhide Bosal with Rawhide cream then tie the Bosal around the shaping block. You can buy Bosal shaping blocks from various makers, or you can make your own custom block to shape a Bosal for the intended horse. Most quality Bosals come shaped pretty well. They should be oval shaped as opposed to round. Again, I recommend shaping the Bosal to the horse you are going to use it on. The Bosal being shaped at right is for a horse with a wider nose.
I think it may be a good idea if you ride often with a Bosal to use several different correctly fitting Bosals. What some people refer to as a "loping Hackamore", which is a braided soft rope Bosal, could be used to change up the feel for the horse, give him a break, and ensure you are not consistently putting pressure on the same spot.
The diamater of the Bosal will have something to do with the amount if pressure you are placing on the nose. Generally, without regard to the material or roughness of the Bosal, the thinner a Bosal is the more pressure it can exert. However, a heavy or weighty, thicker Bosal can also put pressure on the horse's nose just when he carries it.
Some people may be tempted to believe that since you have nothing in the horse's mouth, it will be hard to hurt him riding with a Bosal. This is not true. An ill fitting Bosal, with play at the sides (side buttons) will sore up a horse's nose pretty quick. A improperly placed Bosal, where it is too low on the horse's nose can damage the horse's nose. I would also suggest inspecting your Horse's nose visibly and with your fingers to check for soreness. And I imagine with harsh used buildup on the nose bone could occur.
A Bosal that is not taken care off, such as being dried out or having some of the rawhide braids gets loose and warped, can also sore up a horse's nose. Granted, some rawhide cream on a quality Bosal will keep this from happening and I have only seen rawhide strands warp or turn on cheap Bosals. I have bought most of my Bosal's from Big Bend Saddlery or Craig Cameron's Double Horn Store. I still run my finger around the Bosal, especially the inside that makes contact with the horse, from time to time to check for roughness.
And lastly, quick and heavy hands can make any Bosal, or bit, or even a halter into an abusive tool.
I'm sorry Abrahim if you got more of an answer than you sought, but like my wife will tell you, I don't use 8 words when I can use 30.