Q: The comb on my shotgun is too low and a coach suggests I fit a rubber comb raiser to address the issue. How effective are off-the-shelf comb raisers?

A: A comb-raiser can be a useful stick-on accessory when a gun stock really is too low.  By raising the comb you are now able to keep your master eye in alignment with the target over the rib, when the gun is mounted. It helps ensure you do not lose sight of the bird when the stock meets your face.

If your gun does have a low comb and the master eye loses sight of the target, your other eye will take control of muzzle alignment and send the shot wide of the mark.

Comb raisers are useful things but they should only be viewed as a temporary measure. If, by raising the comb height, you find it easier to hit targets, your next job is to have the wood raised permanently by a professional gunsmith. An experienced fitter will be able to determine by how much the comb needs to be raised.

There are some neat comb raising devices available, but steer clear of those that not only add height, but unwanted width at the point you place your face. Too much bulk could affect eye placement in relation to cast.

If you think comb height (or lack of it) is an issue, then you can temporarily add thin strips of suitable packing material to the top of the stock and hold them down with insulating tape. By raising the height a little at a time you will soon settle on a happy compromise, without affecting the gun’s cast in any way. Once you’ve found the ideal height, send the gun to a gunsmith and have it altered permanently.

You will be pleased to know that this type of work is not at all expensive.

The trouble with rubber comb raisers is that their bulk can also affect the cast of the stock, putting your eye out of lateral alignment with the rib of the gun.

How to alter the comb on a shotgun

See how a gunsmith alters the comb on a Beretta Ultralight shotgun.

How to practise your gun mount at home

There is no substitute for regular mounting practice to achieve a smooth, fluent and efficient mount — bringing the comb…

Drop at comb and heel

Q: In shotgun tests what does drop at comb and heel mean? If they are such important measurements, why do they differ from one gun to another?

A: Imagine a straight line, projected backwards from the line of the rib along the top of the stock.

• Drop at comb is the vertical distance between this line and the front of the comb.
• Drop at heel is the vertical distance between this line and the heel of the stock.

Distances differ from gun to gun for the simple reason that shooters come in different shapes and sizes.

Some have long necks and sloping shoulders, so they generally require a lot of drop: others with shorter necks and straighter shoulders require less drop in order to keep their eye in correct alignment with the rib.

Gun actions also differ in depth and form, and this factor affects drops, too.

This is a generalisation, and the regulation of drops is one of the basic elements of gun-fitting.