How to Build a Custom Gun Stock from a Semi-Inlet
December 03, 2013
The practicality of high-quality synthetics aside, many shooters appreciate the aesthetics of a fine walnut gunstock. If executed properly, a custom stock made from a figured blank of juglans regia (walnut) is a functional piece of art.
Due to the labor-intensive nature of producing a properly inletted, shaped and finished stock, custom masterpieces can be very expensive with "best quality" examples starting at $3000 to 5000, plus the cost of the blank. Such prices are impractical for most folks, but luckily there's another way to own a fine gunstock, which is an ideal pursuit for hobbyists.
An untrained hobbyist can begin transforming a blank of dry walnut into a proper gunstock with a machining method known as duplication. In this process, a stylus and router cut a blank of walnut into a specified pattern. A pattern stock is locked into the router opposite a blank of wood. The craftsman traces the pattern stock onto the blank with a stylus, and the corresponding router cuts the blank to match the path of the stylus. It is a laborious process, but saves dozens of hours with hand tools.
Duplication does not produce a "drop in" gunstock, but rather takes away 90% of the excess material, allowing the builder to focus his attention and patience on the delicate portions of the project.
Duplication can also expose unseen flaws in a stock blank, which saves hours of work. Old trees are commonly filled with bark pockets, old nails, and even bullets — all of which can hide inside even the finest of stock blanks. Such flaws are easily discovered during the duplication process without spending countless hours hand-shaping an unusable blank.
Duplicating with the Pros
After several bad experiences with "bargain" internet gunstock companies, I discovered the duplicating services of Idaho gunmaker Shane Thompson. Thompson is a highly-skilled, custom gunmaker who belongs to the prestigious American Custom Gunmakers Guild, as both a metalsmith and stockmaker. In addition to his custom rifle business, Thompson also offers duplication services to consumers and other custom gunmakers in his trade. He offers a variety of pattern stocks to choose from, using both Dakota and Hoenig duplication machines for his services.
A few years ago, I was headed to Zimbabwe to hunt buffalo, and wanted to build my own stock for the Model 70 in .375 H&H that I'd be using for the hunt. I consulted with Thompson, who emailed me photos of numerous stock blanks. I chose an attractive, modestly-figured, quarter-sawn English Walnut blank with excellent strength characteristics. Thompson crafted me a semi-inlet made from the English Walnut blank, with an ebony tip and a pancake-style cheekpiece.
After previous disappointments with the online bargain stocks, I soon realized the quality of Thompson's work is as good as it gets. When the stock arrived, its exterior surfaces were smooth and well-shaped, and the inletting looked like it had been cut with a laser.
Thompson charges $185 plus the cost of the blank for a semi-inlet, which you can provide or choose from his selection. One-to-one duplications cost $285. Two-piece duplications are more labor-intensive, and run $325 to $500, depending on complexity of inlet and its features. Thompson can also add services for extended tangs, skeleton grip caps or buttplates, steel buttplates, inletted swivels, ebony tips and more custom services are available upon request.
To execute the task of finish-inletting the stock, I referenced the finest book available on the subject — Professional Stockmaking by David Wesbrook. This book provides true step-by-step photos and text "from the eyes of the stockmaker," and is an invaluable resource for anyone attempting to inlet, shape or finish a gunstock.
There are basically two ways to make a gunstock using the duplication method — the semi-inlet and the one-to-one inlet. A semi-inlet stock is made from a chosen pattern, suited to fit a particular rifle's action, magazine and floorplate. The barrel channel is left undersize to fit any barrel profile, and the action inletting is left .030 inches undersize as well. The external features — such as the cheekpiece — can be cut .030 inches larger than the pattern, or left further oversized to allow for more hand shaping.
With a one-to-one inlet, a pattern stock is made out of a sturdy but unattractive blank of walnut and sent to the customer. The customer inlets the stock and shapes the external dimensions to fit their exact desires. Body filler is often used to add material to the exterior, and glass bedding epoxy can be can be used generously as a shortcut to mate the metalwork perfectly to the woodwork. When the customer is satisfied with the pattern stock, it is returned to the duplicator and used as the pattern to cut to within .002-.003 inches of the actual gunstock blank to precise dimensions for a "one-to-one" fit. One thing I learned from this process — when in doubt, consult the duplicator when choosing a blank.
First, secure the semi-inlet stock into a sturdy, padded bench vise. Then, brush inletting black (marking dye) over the metalwork, which is then inserted into the stock using headless, inletting guide screws to ensure proper alignment. Using a rubber or rawhide mallet, strike the top of the action to imprint the inletting black from the steel onto the wood. When the barreled action is removed, black marks appear everywhere the metal touched the wood.
Next, Using chisels, gouges and scrapers, wood is slowly removed and the process is repeated, allowing the metal to sit gradually deeper into the stock. You cannot move too slow when inletting — once wood is removed, it's gone forever. The goal here is for the seams between the wood and metal to be all but invisible when the project is complete, and that takes time — especially for beginners.
My inletting on the .375 H&H turned out pretty good, but it wasn't perfect. To fill in the imperfections and to add strength, I fitted two internal cross bolts made of threaded steel rod, and then glass-bedded the action into the stock. The result was a stock built to resist a lifetime of use in the field.
Once the inletting is complete, the fun begins. The final shaping of the stock's exterior is what separates a generic "one-size-fits-none" factory stock from a functional custom gunstock. At this point, the grip cap should be fitted to help shape the grip properly, and the butt can be cut to length and fitted with the butt plate or recoil pad. Using a selection of rasps and files, the forend can be profiled and shaped, the tip is rounded or swept, and the grip, comb, and cheekpiece are sculpted to fit the shooter's dimensions.
Since the action, barrel, floorplate and trigger have been fitted to the stock at this point, you can shoulder the rifle and dry-fire as you shape the stock to fit your preferences. If the rifle will wear a scope, it should be mounted before the stock is shaped to ensure that the shooter's head will align properly with the optic.
With the shaping complete, the finishing process begins. With the metalwork in the stock — and taped-off if it's not going to be refinished — the stock is progressively sanded to remove the rasp and file marks left by the shaping process. Depending on the severity of the tool marks, sanding can begin with 100, 120 or 150 grit paper, and finish anywhere from 400 to 1000 grit.
Rubber or wood sanding blocks of various shapes are an absolute must to maintain the various lines of the stock without rounding corners or creating ripples that will be visible when the finish is applied. It's a good idea to wait until about halfway through the sanding process to cut the recessed area below ejection port, so the delicate edges don't round off during sanding.
Many stockmakers begin the sanding process by "raising the grain," which entails wiping the exterior of the stock with a wet rag and drying it with a hairdryer or heat gun. The stock is then rubbed with a scotch brite pad to remove the standing grain ends. I like to completely sand the entire stock at least twice with every progressive grit of paper to ensure that I'm getting full coverage. This process can be compared to automotive restoration and refinishing.
Once the stock is sanded to 400 grit, apply the sealer. There are many fine finishing sealers on the market, and each stockmaker has their own idea of what is best. Many top gunmakers in the trade use Daly's Ship'n Shore Sealer and Benmatte Danish tung oil or Seafin teak oil. Since these products are designed for marine use, they resist moisture well, and they are also very simple to apply.
With the stock hanging by a wire hanger through the magazine inlet, cover the stock with sealer inside and out. Continually brush onto the wood over a 48-hour period, until it won't absorb any more sealer. Wipe off any excess sealer with paper towels, and always use proper disposal methods when using finish-soaked rags, as they can spontaneously combust.
Once the sealer is dry, brush on the tung oil using soaking coats for approximately 48 hours. At this point, put the metal back into the stock and wet-sand the wood with 600 grit wet/dry paper, using the tung oil as a lubricant. The slurry of finish and sanding dust is allowed to dry on the surface of the stock to help fill in the pores of the wood. Continue wet sanding with lighter pressure and finer grit papers until less slurry appears each time.
Depending on the stock's appearance at this point, I may hand rub a few drops of tung oil into the finish each day for a week or so. Each time, making sure to build up as much heat as possible and then allowing the stock to dry in a dust-free environment such as a cabinet. Depending on how I want the finish to look, rubbing the stock with a felt pad soaked in rottenstone (a mild abrasive powder) and tung oil can give the final surface a satin glow. The best part about the finishing process — if you make a mistake, you can sand that spot (or the entire stock) down and start over.
After all of the time put into my .375 H&H stock, I wanted the checkering to look as good as the rest of it. Though it's an excellent skill to learn the art of checkering, it's not a common skill in many folk's toolboxes. I sent the stock to Clint Meier at CGM Gunstock Checkering, who executed a pattern that matched my desires at a reasonable hourly rate. After brushing a few coats of tung oil into the checkering, the stock was done and the rifle was ready to go hunting.
Invest whatever you're comfortable with in a blank, and add in a few extra dollars for things like recoil pads and sling swivels. Take your time, and it's possible to create an heirloom for a fraction of the cost a custom maker would charge. The satisfaction of hunting with something you created yourself will far exceed anything even the most impressive checkbook could buy.