I seem to be popular tonight so I will jump in. First of all, I do NOT use a milling machine to inlet a barrel. I use chisels only for that. What I do with the milling machine is get most of that extra wood out of the place where the barrel will go. I do NOT use a milling machine to cut to full depth or width of the barrel. The barrel WILL NOT fit when I am done with the milling machine. That is for bulk wood removal only. After that it all chisels and inletting black.
For you first build if you do not really know what you are doing I would recommend using chisels only. Watch my Tennessee rifle build video series. I inlet that one entirely with chisels. I had a milling machine out in the garage the whole time and did not touch it. It takes some experience to make good use of it. At that time I did not think I had the experience needed to do a good job.
If you want to use a router cut a channel slightly narrower than the width of the bottom barrel flat and almost to full depth of the barrel channel right down the center. That will remove a good amount of wood. Do the rest with chisels. Do not try to cut the angles part with power tools. Chisels can take that out pretty quick. Routers can remove big amounts of wood very fast. That means they can make big mistakes very fast also. A dangerous way to go. It all depends on your skill with a router.
Another method is to use a drill press. Get a drill bit slightly smaller diameter than the width of the bottom barrel flat and drill a line of holes down the center almost to the depth of the barrel channel. That also takes out a lot of wood, but at a slower and more deliberate pace than the router. Use chisels after that.
Safest way is with all chisels. It will take a long time. No matter which way you go, you won't finish tomorrow. But you have a good chance of finishing before the end of January if you keep at it. This does not go fast. You need to have the mindset that a finished rifle in not the goal. The goal is to enjoy the time that you spend working on it and it does not matter how long it takes. Get some audiobooks and just let the world go away for a while.
You have all that extra wood on top. I would just take it off with a small hand saw. Then level off that surface with a rasp and a straight edge.
LawrenceA is right in saying not to use a power tool if you need instruction. Just remember that all of the originals were built without the use of electricity. Power tools are not required. My videos show every step of building with explanation of what I am doing. If you have questions, take some photos and post it here. Most likely you will get a number of answers.
This will be quite a project and it will be tough at times. You have a lot to learn. The good part is that by doing it this way instead of getting one of the easier kits, you will actually learn how to build guns. After this you be fully capable of building from a blank. Then you won't need kits anymore.
