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Started my wife's new '73 stock.


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Fitting and Shaping the Buttstock
 

As you begin working on the buttstock, this is the time to decide whether you want an exact duplicate of the pre-existing wooden stock, or alternatively, if you want to raise or lower the comb or adjust its side to side "cast" angle to suit specific shooter needs.  

 
Adjusting the cast means you will need a wide enough piece of wood for the desired side deviation. Minor elevation or lowering can be done simply, by slightly altering the front-to-back depth angle of the channels milled into the wood for the top and bottom tangs.  But if the angle change will be more than a few degrees, you will want to work the shape and dimensions out on paper, adjusting the drawing that will be used for initial buttstock cut-out.  The top-to-bottom dimension and angle of the grip area of the stock may need to be altered, and the change in comb height may require more or less wood to be left on the top.   If you are working with a valuable piece of wood, you might want to try a prototype first, made from pine or other soft inexpensive wood.  Unfortunately, that almost doubles the overall work. 
 
Once you have the outline you want to use it is a simple matter of laying it out on the wood.  Pay attention to things like where to position the prettiest silk or patterns (not under the Butt wrap or obscured by checkering).  Also look at the grain lines for strength and stability.  Ideally, the grain lines should run nearly in parallel with the length of the stock.  If it is possible, incorporate curved grain lines into the curved grip area to add strength and split resistance.  
 
The height of the buttstock grip area must end up  to be almost exactly the distance between the outside of both tangs after final finishing .  Because the tang surfaces are usually curved in cross section, The wood of the stock needs to make a smooth transition with the edges of the tangs.  Any mismatch will be very obvious in the finished stock. In cutting out the stock profile, you will need to look carefully at what sanding will be needed on your particular wood and be sure to leave enough proud wood for finishing.   (also remember the added material height when you are setting up the buttstock for milling of the tang recesses.)
 
Milling the tang recesses
 
Both the top and bottom tangs are tapered longitudinally.  In setting up for milling, that depth differential needs to be addressed.  An easy way to do that is to measure the tang thickness at the front and rear, and mark those depths at appropriate positions on the outside of the buttstock blank.   (adding in the extra material thickness described above).  Then clamp the workpiece lightly in the machining vise.  Lift one end of the workpiece to level the marks to the top of the vise. ( I used a precision machinists parallel bar on top of the vice and adjusted the front and rear marks on the wood to match the parallel top edge), then tighten the vice securely.  Now the milling cutter  will cut the taper fairly accurately as the cutter passes across parallel to the top of the vise. That procedure will work for both the top and bottom tang and also for the secondary, narrower recess slot that is more deeply cut above  the bottom tang recesse to accommodate the trigger assembly, hammer and mainspring.  
 
Both tang recesses can be milled with a 1/2" mill.  The tangs on my subject rifle were just a bit wider, which allowed some final hand fitting with a sanding stick.   The deeper, narrower secondary bottom recess can be cut with a 3/8" mill (see photo). Be sure to measure your tang width, as they could vary between manufacturers and production dates.  
 
The length of the milled recesses will need to be determined by measurements on a particular rifle.  Measure the recesses on the original stock.  Be sure to measure from the longest tip of the original  buttstock grip and not from the r
shorter edge of the rebate. Otherwise the tang recesses will not be milled long enough to allow the rebated end to fit into the recess of the receiver. 
 
 The fit of wood to the tangs is very visible, so work very carefully.  Once you remove the workpiece from the machine vise, your depth-indexing will be lost, and fitting after that point must be done by hand cutting.  Over-cuts cannot be corrected without major piecing in of replacement wood, which is itself an artform -- at best.  So measure and mill the slots very carefully.  Measure and re-measure often during milling operations. 
 
Once the slots are cut, the stock should mount on the receiver.   The front end of the stock must be scribed at the meet-point with the metal of the receiver, similarly to the way the marking was done for the two ends of the fore-end. 
 
 During scribing, be sure not to rub through the blueing or other finish of the rear metal edge of the receiver with a hard scribing tool.  A hard pencil should be adequate.  A shiny wear mark on the receiver will stand out visibly on the finished gun.  
 
When the inletting is complete, the buttstock needs to be removed from the rifle and drilled for the tang connecting screw.  The hole is 3/16".  The hole can be set up and accurately drilled on a drill press or milling machine.  Be sure that the stock is solidly held in the drilling vise and that the sides of the stock are EXACTLY aligned with the drill bit. In addition, the stock must be level in the vise lengthwise so that the drill bit is EXACTLY perpendicular to the top line of the top tang (should now  be parallel alignment to the top surface of the wood in the grip area).  
 
The hole must be quite exact in order to line up with the two tangs.  But more importantly, it must not wander to either side.  If it does, it is likely to emerge outside of the tang slot, creating a hard-to-repair visual defect and necessitating the hole being filled and redrilled.  
 
 I like to carefully measure and mark the hole position at top and bottom.  I then clamp the top of the grip area of the stock flat in the vise, then pilot drill the hole with a smaller size drill to verify the alignment.  Only when I am satisfied that the alignment is correct do I step up to the 3/16" bit, piloting on the smaller diameter hole.  Because this boring is concealed beneath the tangs, you can make multiple tries with the small drill to get the alignment exact, then drill the larger hole using that accurate set-up. 
 
Shaping the Buttstock
 
Once the hole is bored and the stock is fitted to the gun with the tang screw hole alignment tested, the stock can be shaped.  The shaping process itself is not difficult , as long as you work carefully and compare back to the original stock often.  A pin-style contour gauge and caliper are a huge help in the shaping process.  I do much of the shaping work on the broad rear half of the stock on a disc sander.  I then rough shape the grip on a 2" carbide drum sander chucked in the drill press.  Finer shaping is done by hand with medium rasps, followed by sanding with an orbital sander.  
 
DO NOT attempt to sand the front of the stock -- the area that will interface with the receiver -- using a power sander.  Instead, work slowly with flat sanding sticks, as described above for the fore-end. 
 
The final feature of the buttstock is a cap for the rear of the stock.  This can be omitted, but normally it is a good idea to hard-cap the end to protect the end grain from splitting or other damage in case the gun is dropped or bumped against hard surfaces.  Caps can be metal, hardwood, plastic, or a soft recoil pad.  If the original (replaced) stock has an end plate, it is easy just to reuse it.  The end cap is probably less necessary if you plan to use a protective butt-wrap.  If you do want a cap, it needs to be installed prior to final sanding or applying finish.  For my wife's rifle, I did not install a cap, but I did install a butt-wrap after final finishing.
 
By now you will be able to see your fit quality.  If you worked with care, this is a satisfying stage in the process.  Only final finishing of both buttstick and fore-end  remains to be done.  
 
Photos below show use of a parallel bar to align the marks for milling the tapered depth recesses. The top of the p-bar is set at the depth of cut and the cutter is aligned to the top of the bar. 
 
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Edited by Dusty Devil Dale
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Posted (edited)

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Final Finishing

 
There are nearly as many good wood finishing methods as there are woodworkers.  For gunstocks, just about everything has been tried, ranging from rub-on essential plant oils, like Tung Oil, to a variety of brush-on or spray-applied finishes and many combinations.  
 
 I really like the appearance and durability of the oil finishes, but I don't have the time and patience to make the numerous repeated applications and wait times  needed to get a really good looking result.  
 
My own preference is a spray application of automotive-grade, catalyzed, water-based Urethane finish, otherwise known as "clear coat urethane" (see picture). It is available in a variety of gloss levels.  It is pricey, at about $220/gallon, but is easy and relatively fool-proof to apply, allows sufficient work time (sets up in 45 minutes on an average 70 deg day), self-levels on the wood surface, and is unaffected by normal gun chemicals.  (even laquer thinner is slow to affect it.)  It is tough, reasonably easy to repair -- usually without having to remove the stock-- easily sanded to a high quality surface, and can be hand rubbed with powdered rottenstone, paste auto polish,  pumice, or a number of other ultra-fine abrasives to achieve whatever luster is desired.  I used it on this project, following the method below:. 
1.  Shape and inlet the stock 
 
2.  File the surfaces semi-smooth.
 
3.  Sand the surface working through the grades, down to 400 grit.
 
4.  Burnish the entire surface with a smooth stainless steel burnisher to compress grain, smooth most grain defects and reveal dents.
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5.  Wet the surface with a wetted  towel to raise the grain.  
 
6. Apply a steam iron through the wet towel as needed to raise any dents. 
 
7.  Dry, re-burnish,  then re-sand down to 600 grit or finer, and wipe down with a tack rag.
 
8. Lightly spray the surface with water-based Urethane, and allow to dry.
 
9.  Wet sand the entire surface enough to inspect for tiny defects (appear as shiny dents skipped over by the sandpaper -- see photo below)
 
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10.  spot-sand defects with a 320-grit covered block. 
 
11.  Re-spray with Urethane and dry.
 
12.  Lightly wet sand with 400 grit.
 
13. Lightly re-spray two more times, separated by light sanding with 400 or 600. 
 
14.  Dry overnight
 
15.  Lightly go over the surface  with 800 grit, then rub out the entire surface with an ultra-fine abrasive made into a thick paste with a drop or two of mineral oil.  I rub it on with a piece of soft cotton towel.  As it dries on the rag, it brings out the eggshell finish I prefer.  (I actually prefer to use Turtle brand automotive paste polish as pictured).
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16.  Wipe the completed project down with a soft cloth and assemble the rifle.
 
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The photo above shows the fore-end with the shine still present prior to being rubbed with fine abrasive.  The buttstock has been rubbed to an eggshell finish. 
 
Note:  In spraying the finish coats, don't fret about tiny dust particles. They will disappear completely in wet sanding and rub-out.
 
The finishing process above looks a bit intimidating, but all except the last dry and rub-out steps can easily be done in a single afternoon.
 
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Finished buttstock with butt wrap. 
Edited by Dusty Devil Dale
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