Shotgun Adjustable Comb Installation Tricks

Shotgun fitting is a popular custom service and I’m seeing it growing. While not anew idea—the gun stock has been changing over the centuries to become more functional and convenient—it took along time to develop an understanding among shooters how fit of the shotgun stock plays a major role in placing the shot where it is expected. Shooting at flying targets requires pointing rather than aiming and this pointing is a rapid and intuitive motion, combined with concentration on the flying target and leading it.

In such conditions, with limited time and multiple variables, only the correct fit of the gun can insure the impact is where the shooter intends, all other mistakes excluded. Normally, misfit means a physical inability of the shooter to line up the leading eye with the top rib. In other Aluminum plates may be round or rectangular and are 0.25" thick. words, the projection of the rib-line cannot be placed into the center of the eye, though trap shooters often require "high-rib" adjustment to lead the raising target.

Misfit often happens with an overly-high comb, insufficient cast-off or length, or other dimensions of the stock inconsistent with the body proportions of a particular shooter. Even if a line up can be achieved— at the cost of inconvenient and awkward shouldering—it is a misfit. Such an awkward shouldering means some muscles are abnormally tightened to achieve a sighting picture.

The concentration on the flying target and trigger pull distracts attention from the muscle control and the body relieves muscles, shifting the point of impact. That mostly goes unnoticed since the recoil smashes these subtle feelings. To eliminate problems with misfit there is a process of fitting the gun to a shooter.

Fitting Process Fitting the gun to a shooter is a process of changing the stock geometry so the aiming eye of the shooter is lined up with the top rib of the shotgun while the gun shouldering remains comfortable and correct. This correct shouldering means several things, but at the very least the shooter’s cheek should be firmly placed on the comb and the stock-butt should be properly on the shoulder.

With this achieved, fit will be provided by changing several adjustable parameters of the stock, such as drop at the comb, drop at the hill, cast, length of pull, and pitch. Sometimes there is a need in changing the configuration of the pistol grip, mostly dependent on the size of the shooter’s palm. Another, non-obvious adjustment is the angle (twist) of the buttpad. In some cases, this may prevent the canting of the gun.

I’ve found in my practice this mostly happens not because of the buttpad position, as many would think, but because the shooter is intuitively moving the ribline closer to his eye. Regardless, it’s normal for some of the mentioned five dimensions to need changing for a particular shooter. There are some fine publications on shotgun fitting and

The hollow tunnel does not allow proper installation of the Graco hardware for two reasons. First, there is not enough wood for holding the part strong enough after gluing. Second, milling a 0.25" recess and gluing the base would completely obstruct the access to a stock-screw. I specifically recommend Stock Fitter’s Bible by Rollin Oswald and Gunfitting: The Quest for Perfection for Shotguns and Rifles by Michael Yardley and Paul Roberts.

I find these books promote solid understanding of gun fit and uncover hidden reasons behind the lost targets. Making Adjustments The oldest method of changing the stock dimensions for fitting is bending it in a special cradle with heat applied to the grip area. Such bending, though, is best suitable for the traditional, straight English stocks that are finished with oil. It is easy to heat their slim grip area through the thickness of the wood, which is necessary for the efficient bending. Traditions have changed.

The stocks around the world have become bulkier, have pistol grips, thick combs, and are often finished with epoxy. Also, over-and-under shotguns and some side-by-sides have a steel stock-screw holding the action and stock together. All these features are obstacles for bending. While bending is some- The dimensions are not critical but a 1" width allows usage of the 1" end mill for preparation of the recess.

The base is then glued to the wood by side flanges. times still used, it no longer is the best option for fitting anymore and many bulky stocks have been damaged during attempts of bending them. There are a number of alternative solutions, including hardware for adjustable combs, buttplates, and their combinations with recoil-suppressors. Among the most popular manufacturers are Graco, Breako, CSP, and others. More and more guns appear with factory-installed adjustable stocks.

It does not exclude, though, the need for custom installation of adjustable combs by the gunsmith. Acquiring hardware, however, does not solve all the problems. The subject of this article is solely related to problems of the adjustable comb installation on the shotguns. Adjustable Comb Installation Normally, installation of the adjustable comb is straightforward. The gunsmith locates the empties in the stock, accordingly cut off a portion of the stock, and install the set of the available hardware.

Cutting out apart of the stock with a bandsaw requires some attention for producing a straight and parallel cut. For this matter I use a simple jig along with paper-tape on the stock to protect from scratches and to draw cut lines. Some similar steps were described by Walter Gaskins in his September 2011 article, "Installing Adjustable Combs On Gunstocks." Gaskins also shows how to provide a soft leather cover on the comb.

Some shooters find this feature useful for reducing recoil into the cheek and more comfortable for touch. This type of recoil, though, is a result of the shotgun swinging around the

From left to right, 10-24 stage screw with turned-reduced head, standard stage screw before reducing the head, post showing 10-24 thread, shallow recess to accommodate the square protruding through the plate, and the installed post with slot for screwdriver. shoulder by the muzzle flip. In many cases, this flip and resulting recoil can be reduced by porting the barrels and providing a proper pitch of the stock. But let’s get back to our major subject.

After cutting the comb you need to install hardware for enabling fourway (up, down, left, and right) comb adjustment. In most cases, gunsmiths choose Graco Adjustable Comb Hardware (graco-corp.com, because it’s simple to install and use while being inexpensive. Graco bases may be either round or rectangular. The round ones are easier to install—just mill two recesses one-inch in diameter and a quarter inch in depth and glue the bases in. The disadvantage of these bases is they may be misaligned during installation.

This problem is taken away by the rectangular base, but making an accurate rectangular inlet for it takes more effort. I often round the ends of these bases in order to use the same 1" end-mill as for the round bases. In both cases, depth of the wood at the inlet area should be sufficient for complete deepening the base to 0.25" into the wood while having some support under its bottom. Unfortunately, quite often, cutting the comb of the sufficient depth brings you right into the hollow stock tunnel.

Sometimes the rectangular base can still be installed in the hollow tunnel by gluing it to the walls but the major problem is that, no matter what, the base is thick and blocks at least 0.25" of the tunnel. This is often enough to prevent even a screwdriver or socket wrench from reaching the head of the stock-screw, let alone removing the screw from the stock.

Cutting the shallow comb to avoid reaching the tunnel is not the answer since the shallow comb disturbs the shooter with sharp edges of the cut and does not have enough depth for installing the bushings. Naturally, the biggest obstacle for the installation in such cases is a thickness of the Graco-like bases. Installation Solution Facing this problem quite often, I finally put it to an end by significant reduction of the base thickness.

My main principle for achieving this is using reverted 10×24 carriage bolts and a thin hi-carbon, channel-shaped 3/64" steel plate. The bolt head should be turned down to a same thickness of 3/64" or about 1mm. Note the thin profile of the new hardware and the turneddown screwhead as compared to the original screw. I’ve provided a drawing of the plate with dimensions used in my practice.

The dimensions are not critical but for installation of this plate into the stock it is convenient to have 1" width for using the 1" mill to prepare the recess in the wood. The slots for the bolt-squares prevent the bolts from rotation when the posts are screwed upon them. The posts need to have the thread corresponding to the thread on the carriage bolts. I use bolts with 10- 24 thread. The posts need a shallow relief for the square protruding through the base upward.

For putting torque on the post, a simple slot on the top is made wide enough for using screwdriver, coin, or other flat object. The base is attached to the stock by gluing into the channel milled in the wood. No screws are needed. The wide sides of the base provide enough area for holding it strong. I use J-B Weld Wood Weld. Once the base is completely installed along with the plate with posts, you are ready for the comb.

The comb portion is not discussed here because it is straightforward and does not present any surprises. As usual, two bushings are installed into the comb and threaded holes are provided in each bushing for the set screws. AG