THE SADDLE GULLET
The saddle gullet is the cut out or tunnel underneath the FORK and rides over the horse's withers. The design of the fork and the angle of the bars of the SADDLE TREE determine the width and height of the gullet.
It's important that the GULLET have the right amount of clearance over the withers. If the gullet height is too short, the saddle will rub on the horse's withers. If the gullet width is too wide, the saddle will sit too low on the shoulders, and also rub ont the horse's withers. Rubbed withers equals unhappy horse.
A good rule of thumb to use for gullet fit is that there should be clearance of two to four fingers-widths between the withers and the gullet.
Unfortunately there are no standards for gullet measurement within the saddle industry. You'll find different measurements among different saddle makers. One thing to keep in mind is that gullet measurements are taken on a raw saddle tree and not on a finished saddle. Once a saddle is finished, there's really no way to determine the gullet width.
Gullet widths as described by Richard L Sherer in " Horseman's Handbook of Weswtern Saddles" are;
Regular Quarter Horse Bars: 5 /34"
Semi-Quarter horse bars: 6"
Full Quarter Horse Bars: 6 1/4 " to 6 1/2"
Extra Wide Quarter Horse Bars: 6 3/4" to 7"
Arabian bars: 6 1/4 " to 6 3/4" (Has a flatter pitch than quarter horse bars.)