I have approached this article as an instructor explaining gun fit and all its facets to a client who has approached me with various shooting issues. Common complaints can be, The gun never shoots where I am looking, I can really feel the recoil and my face is always bruised, I have just bought a new gun, and my mount has no consistency.
It is amazing how many people shooting have a poorly fitting gun, and regrettably creates bad habits to compensate for the lack of gun fit, this also contributes to people never improving on their scores, and missing the same targets every week.
There are two types of gun fit, firstly there is the novice fit, this is purely to make sure there gun is a reasonable fit and safe to get them started on the road to developing their style and confidence, secondly and more importantly is the gun fit for the experienced gun. I say this is more important purely because the experienced shot has developed a reasonably consistent mount and a style of shooting to consistently break targets.
As an instructor we have various tools to test and check the different aspects of fit for the client, firstly there is the Pattern Plate, first shots to be taken with gun mounted at varying ranges, this will expose any trends and inconsistencies with your clients shooting positioning. Once you have gained results with the gun mounted, you can then move on to an un-mounted gun, to check on any variations here.
Pattern plates are not the only ways of assessing a clients gun fit, there are a selection of targets that you can use to give you varying results, a) Straight Going Away Bird-this can help assess the guns cast, also whether the gun is firing to high, b) High Bird Overhead-this is a very good test for stock length, too long and it will bind the swing, too short and the client feels extra recoil, c) Rising Targets-this will show if the gun is shooting low, d) Fast Crossers-this a good test for reviewing stock length, felt recoil and if there are any problems with an add on such as recoil pads sticking, e) Hard Quartering Birds from left and right, you will gain more information on cast, drop, and pitch, it also throws up any subtle issues.
The use of add-ons as opposed to a try gun, as an instructor I must admit I prefer using add-ons and the client’s gun, this way you are working with a gun already the right length and weight for the clients. Although there is a case for the try gun if your client is looking to have a new handmade gun from a specialist gun maker.
Before we set sail on the ship that is gun fitting, we must first check and confirm with varying tests the clients eye dominance, there is no point in making any changes to the clients stock if you don’t know if they are right or left eye dominant, or have central vision and which shoulder they are shooting off. Listed below are the areas we are going to review.
Length of pull
Cast
Pitch (Stand)
Drop (Bend)
Grip
Gun weight, Balance, Barrel length and Weight
Rib height
Length of pull, or just called length, this is the distance measured from the trigger to the middle of the Butt Sole. It is worth measuring to the Toe and Heel at this point as it will help to determine the Pitch, which will be covered later.
A new gun from the factory will have a stock length anywhere between 14.1/4 inches to 14.3/4 inches. Most adults will want a stock measuring between 14” and 16”, the longer you can manage to have the stock the better especially for disciplines such as sporting. It is good to carry out a few basic tests before working measurements are made, and any changes to the stock are made. Obvious things to look for, are quality of mount, is it smooth, another check you can do at the start of the processes is to check if there is at least two figure gap between the end of the nose and back of the grip hand thumb. You can then get your client to shoot a few high over head birds as this will tell you if the stock is to long as it will tie up there swing or if to short they will feel a lot more recoil.
Once you have gathered all this information you are ready to note your findings and then move onto the next stage of gun fit, do not be too hasty to make change straight away as other measurements may affect the final outcome. My closing notes on this subject are on heavy and light guns, heavier guns will need a shorter stock, and where as the lighter gun is best served with a longer stock. More information is available in a selection of books listed at the end of this article; this applies to all sections of gunfit.
Cast, we talk about cast in two plains, for the right handed gun we cast to the right, known as Cast-Off Stock, as opposed to the left handed gun which is cast to the left, and is known as Cast-On Stock.
There are a number of variables we will need to consider, too much cast and we can weaken the stock and increase the felt recoil, too little cast and we will not achieve the desired alignment of the eye to the rib. It is also important as an instructor to pay close attention to your clients build and the shape of their head, and as discussed at the start of the article eye dominance is key.
If we compare a client with a broad chest as opposed to Mr. Average, our client with the broad chest is going to need slightly more Cast and they will require the Stock Sole to be angled, where as our friend Mr Average should be fine with factory standard dimensions measured at Heel and Toe of 1/8” and 3/16” respectively.
When we start to asses cast, as mentioned before the eye dominance is key, if your client has cross dominance and they won’t shoot off the opposite shoulder, they are going to have a large degree of Cast, almost forming a dogleg, the same can apply for a client with central vision, it is also worth noting the width between the eyes, as this also can affect the percentage of cast and relationship of the eye to the rib.
Apart from a visual assessment, which the client is mounting in the right position, you can use other tools to make your assessments, such as the Pattern Plate, Driven Targets, and Going Away Targets. Once you have made your decision as to what your client requires, you must decide on the method to use, the first one of a choice of three is to, Angle to one side the full length of the comb, or you might decide it would be best to Offset the comb only, and finally you could have the Stock swept (Hollowed). You cannot rush any of these procedures as they all tie in together to give the client a stock that is right and does what they want.
Pitch (Stand), As mentioned in the section on Length, Pitch is affected by the measurements to Heel, Bump and Toe. When discussing Pitch we are referring to the angle of the Stock Sole, and its relationship to the Rib and Bore. A common method of measurement is to use the floor and wall, although this sounds like a good way unless the floor and wall are both flat and square, the measurement will never be true. It is best to use a purpose made jig, or purposely designed tools for the job.
As with all the measurements needed for gunfit, Pitch is key to mount, placement of the gun in the shoulder, plus the variations between Negative or Positive Pitch which will affect a gun shooting high or low. With guns being set up for Sporting Clays or Game Shooting you would be looking to set a Pitch down measurement. Average figures for Pitch would be for a O/U 5-6 degrees, 2.1/2-3 inches, unlike a S/S which would require slightly less, 4 degrees, 2 inches, that aside the real acid test is to end up with your stock comfortable, and the full length of the But-Sole to be in contact with your shoulder when properly mounted.
Lastly we are looking for the build of our client, where they place the gun to the shoulder and how little or how much of a curve you will require in the But-Sole, to achieve a clean and positive contact with the shoulder.
Drop (Bend), Your measurements for this must be completely exact as the top edge of the Butt will be set relative to the Sighting Rib. All guns must have a certain amount of Drop or else the gun when mounted will always appear above the point of aim. The Drop is primarily measured at Comb and Heel, but it is advisable to also take the measurement at Face, as this, out of all three measurements will have the biggest bearing on the eyes vertical relationship to the barrels and target.
As with all your gunfit measurements the clients build and head shape and size play a crucial part in the final setup. Points to note are, in most men the distance from the cheekbone to the pupils centre is often greater than in women and this repeats for a child, due to Skull shape and Size. Because of this you will find women need a higher Comb than men and children again will need an even higher Comb than women.
When starting to configure alterations for Drop, you should always work from the rear starting with Drop at Shoulder, and then work your way forward with Drop at Face and finally Drop at Comb. With a Sporting Gun you are looking for a figure of 8 when the mounted gun, (Empty and Checked) is viewed from end of the barrels so the pupil sits just on the Breach. Further information can be found in the recommended reading at the end.
Grip, Not often addressed but still an integral part of the right fitting gun. If the Grip is of the wrong size and the client cannot grip it properly, there muzzle control is reduced and reaction to the bird is compromised. It will also have an effect on the felt recoil as more experienced shots take a considerable amount of recoil through their hands.
A good fitting grip can influence many variables, such as the vertical relationship between the Eye and the Comb, a good grip will keep the hand in a secure position allowing the trigger finger to naturally fall into position with ease. The different styles of grips will suit different disciplines, but all must have the right effect during recoil, and fill the hand completely. The type of Grip recommended for both Sporting and Game shooting is one that is less angled than a Grip set up for a Trap gun.
Gun Weight, Balance, Barrel Length and Weight, There is not a great deal to explain about Weight and Balance, the weight of the gun these days is purely down to preference. The current trend is for heavier guns, depending on the manufacturer of choice, the average weight for a gun length of 28-29 inches is 6lb 10oz.
Obviously the weight split between the barrels and the stock can have a bearing on the guns balance, it is said that a well balanced gun should be balanced near the hinge pin. A gun made for sporting with multi chokes will have to be made neither to light at the front or rear. To alter the balance you can place lead in the butt of the stock, the same can be done to the barrels by using glaziers lead strips. To lose weight from the barrels you can have them overboard by a professional gunsmith, again all this is dependent on the clients build and their chosen discipline.
Rib Height, Something that is often altered to reduce the weight, width or the pitch of the Rib, most of the mass produced market have a Rib pitch that is not ideal , unless a purpose built model is purchased from a selected group of companies that as a matter of course supply an Adjustable Rib.
A gun with a high Rib will have a tendency to shoot low, where as a Tapered Rib will draw your eye more to the target, and also have the illusion of elongating the barrels, this set up would be more ideal for a Sporting Gun.
Article written by Mark King of Clay to Game Services – Shooting Instructor www.clay-to-game.co.uk.
References and Further Reading, For more information about all the different facets of Gun Fit, and all the areas discussed above I have listed a few books used for reference and recommended for further reading on the subject.
| Breaking Clays | By Chris Batha |
| The Shotgun, A shooting Instructors Handbook | By Michael Yardley |
| Brake’em All, The Complete Guide to Fixing Clay Target Shooting Problems | By McDaniel & Taylor |
| Gun Fitting, The Quest For Perfection For Shotgun & Rifles | By Michael Yardley |
| Game Shooting | By Robert Churchill |
