Gumboman: it looks like I may have created a monster here. There are plenty of DVD's and video's on this subject, and this subject is almost beyond the scope of this venue. But I will discuss my process and add a few pictures to clarify. I don't think I'll be doing a complete tutorial on 'Building a Hawken Rifle"!!
Your first step is to acquire or create a plan - a drawing on good paper to which you can refer throughout the build. I use poster board or "Bristol board" I buy at the drug store.
Next, make a pattern that you can lay on the wood and trace to get your profile. I like making them out of 1/8" lexan, so I can see the grain through the pattern, for wrist orientation, or to avoid faults in the board. But a door skin or stiff paper can be used too.
I cut out the profile right next to the line, but someone just starting out may only want to do the forestock from the breech to the muzzle end, so that if you must go deeper, you are not committed to a stock already cut to the line. Once the barrel is in, return to your pattern and finish drawing in the bottom lines and butt stock.
Plane the top of the barrel plane flat and square. Measure the barrel's dimension at the breech, minus the plug, and where the barrel exits the wood at the entry pipe, in this case, since it's a half stock and the barrel has a straight taper. This works too with a parallel barrel. Write down these measurements right on the wood. While you're at it, make a felt pen mark every three inches along the barrel from the breech forward, measure these dimensions and write them down on the wood. More later.
I inlet the barrel with chisels, so I only inlet half of it (the bottom half - HA) So I cut away the wood down to the middle line of the barrel, leaving maybe .20" for removal once the barrel is in. What's important here, is to make sure you leave some wood at the breech end - perhaps .020" or even .062", so you'll have some clean up wood later, after the barrel and tang are in.
Draw a centre line completely around the stock. Lay out the barrel inlet area on either side of the centre line. Clamp a straight edge down to the top of the forestock right on the dots on the right side of the centre line, and with a sharp stiff blade, cut along the straight edge, gently at first, ensuring the blade is perpendicular to the wood, and then deeper. Go in as deep as you dare - I go in about 3/32" - 1/8". Now move the straight edge over to the left hand side of the centre line, and repeat. These two cuts are the extreme layout lines of your barrel, so make sure you are not wider than your barrel.
With a flat chisel; I use a 1/2" - cut toward the cut from the inside of the channel removing a long sliver of wood. Again, until you get a feel for it, make your chip small at first. A picture or two here might be useful. These are not in order but you can get the idea.
You can deepen those cuts to almost the full depth of the side flats of the barrel - or half of the flat I should say, but don't go deeper than that. Now, watching the orientation of the grain, use a big gouge and a mallet to remove the bulk of the wood inside the channel. Here's where those measurements you wrote on the wood come in handy. Use the wire end of your Vernier's Calipers to measure down into the channel, stopping the cutting with a little wood yet to remove. How much is a little? Depends on your experience and bravery! I go down until I have around .025" left to take out.
And here's another thing I do to help make those measurements exact. I divide the barrel's diameter (across the flats) by two and add the thickness of my 6" steel ruler, and right that dimension down on the wood, opposite each 3" mark along the forestock. Now I place the steel ruler across the channel, and use the end of the Vernier's to extend the 'wire' down into the channel, to check the depth. This puts you directly over the centre of the channel. Notice above I told you to measure the barrel every three inches and write that down on the wood. This step I just described that's it's place. I hope I haven't confused you too much!
Now use a flat chisel about 3/8" wide or a little narrower, to cut the bottom flat, right down to your finished dimension. Then cut away the angled flats with the same chisel. I use a left and right hand skew chisel to cut the sharp breech end angle flats of the channel. By now, you will have tried the barrel in the channel. A transfer pigment helps spot where it is too tight or does not want to go down. I ran out of Jarrow's inletting black, so on the last tow rifles I used a tube of lipstick I scored from my wife. I use an old toothbrush to apply a very thin coating of the grease, lay the barrel squarely into the channel, and give it a tap with a mallet. Cut away the colour, repeating the process until the barrel bottoms. I made a scraper out of a worn out file by bending the last 1 1/2" over at a little more than 90 degrees under red heat. I ground the end to an octagonal shape and sharpened it. It peels wood out quickly, and can get away from you, so go slowly.
It takes me about four hours, I guess, to inlet a 1 1/8" tapered barrel into a half stock of hard maple, and it's the last .010" - .015" that takes the time. There are likely better and easier ways to do this work, but being self taught, I stick with what has worked for me 'til now. One better, and faster method, is to send the wood and barrel to folks like Mark Wheland, David Rase, David Keck, to name a few, and they'll do an unbelievably better job that you or I can. If you count your time as worth anything, and have already done fifty this way, you'll appreciate their services...I do.
Now the tang...
As you detective types have probably noticed, this is not the current build, but one I did a couple years ago. I didn't document the most recent one as detailed as this old guy, but the process is the same.