Gun fitting is often portrayed as something of a mystical art, known only to a select few. The latter is probably true, because few shooting instructors ever get the chance to learn gun fitting from someone who knows what they are talking about. For this reason gun fitting sometimes gets a bad reputation, but this is not the fault of gun fitting, but untrained gun fitters. There's nothing mystical about it, though, just knowledge, experience and a helping of commonsense. An adjustable gun, or try-gun, is required, too, but simply owning a try-gun does not make a person a gun fitter!
Although it should have been obvious from the outset, it wasn’t until we began to run Gun Fit courses that it became apparent that the gun fitter also had to be a very competent coach. Without this basic ability gun fitting is not possible, since it only by exercising an experienced eye that a good or poor gun fit can be determined.
How important gun fitting is to you depends on your ambitions. If you are a happy 50-targets-a-fortnight shooter then an off-the peg gun will probably suit you well enough. If, on the other hand, you are shooting 10,000 plus clays a year then you are serious about the sport. You care about performing at your best. You will be looking for every little advantage to help your scores improve. You definitely need to look into gun fit, as it can give you a significant edge. As an example, when I am working with an Olympic shooter achieving a perfect gun fit is absolutely paramount from the outset. Serious training with an ill-fitting gun is a waste of money, time and effort.
Gun ftting seeks to achieve three basic dimensions. The length of the stock, the bend or drop of the stock relative to the top rib, and the cast. The latter is the set of the stock relative to the rib when viewed from above. It is very rarely dead straight, and is set either to the right of centre (known as cast-off) or to the left of centre (cast-on).
The stock length is always the first to be determined, as wrong length will distort the other two dimensions. The next is the bend, or drop. This affects how high or low the gun shoots when mounted correctly. Too much bend makes the gun shoot low, and vice versa. Too much bend can also mean the eye loses sight of the target behind the breech of the gun. This can cause all sorts of problems. This is why bend is always determined before cast. Because of the relationship between cheek and eye most people need a degree of cast, either off or on depending from which shoulder they shoot.
So these are the three basic dimensions, but there are others that discerning shooters must examine. A particular complaint of mine is the grip on many over-and-under guns these days, which is too thick. This is especially so with so-called anatomic grips, or palm swells. Just look at squash & tennis racquet grips, or those of cricket & baseball bats. Or the handle of any tool such as a hammer or screw driver or chisel. They are all very slim so that the thumb can wrap around and sit lightly on the fingers. Thus good control and a firm grip is achieved with little effort. So it should be with a gun
Distance from pistol grip to trigger is also a factor, one where many people with small hands have trouble. If the trigger finger is unable to exert pressure in the trigger’s direction of travel and instead pushes at it sideways then trigger pulls, even if perfect, will feel heavy and variable.
There are other important factors, too. Weight is one. Many guns are far too heavy and poorly balanced. Trigger pulls also must be set correctly. Too light is dangerous, too heavy can cause a multitude of problems.
Gun fitting is important if you take your shooting at all seriously. If you have ambitions to improve then get your gun sorted out before you expend a lot of time and effort with something that might not suit you.