Instructions
Understand the function of a hackamore. Riders have many reasons for choosing a hackamore and whatever the reason, it is important to understand that while a horse may be controlled by force with a bit, he must be trained to obey the rider's signals when using a hackamore. Unkind and insensitive use of a hackamore can create resistance and a lack of communication from the horse that will not easily be restored.
Consider the simple bosal. The simplest and oldest form of hackamore consists of a bosal, a thick plaited noseband made from rawhide or cable braided over a core. The leather bosals fit more closely and are more comfortable for the horse and different sized bosals may be used. The bosal must be adjusted correctly to fit just at the end of the nose bone. If you have a good rapport with your horse and she is easy to control, this type of hackamore is probably all you will need and it is often used by endurance riders.
Investigate the "side pull hackamore". Although often referred to as a hackamore, this is really more accurately described as a bitless bridle. It has a leather noseband with rings on each side to accommodate the reins. The horse's head is turned by a direct pull on either side of the reins. When the reins are pulled back, the noseband exerts some pressure on the nose and under the chin. This type of hackamore is good for training young horses and if your horse is young or inexperienced it may be a good tool to prepare a horse for a true hackamore with a bosal.
Choose a mechanical hackamore if you have a lively horse. If you and horse are into show jumping, eventing or other fast and exciting sports, or if your horse is not always easy to control, the mechanical hackamore may be your best option. This has shanks to which the reins are attached and a chin strap that exerts pressure in the same way a curb bit works. The English Jumping Hackamore is virtually the same thing. A thicker noseband is kindest and the chin strap should allow two fingers to fit between it and the horse's chin.
How to Choose a Hackamore
A rider may choose to use a hackamore or bitless bridle for many reasons. Today the term "hackamore" is loosely used to describe a bitless bridle, although the only true hackamore is that used for centuries by South and Central American vaqueros. It is made up of a bosal or plaited noseband with a knot on the underside to which the reins or single mecate hair rein are attached. Some horses have sensitive mouths and are calmer without a bit, but a hackamore can be just as painful and uncomfortable for a horse if fitted incorrectly or used by an insensitive rider.