Posted for Super Badger:
Here's a short explanation of how I added a picatinny rail to the forend of my practical bolt gun
Using a 3/16'' square cut end mill along with an X-Y vice and drill press, I carefully machined a slot that would accomodate the piece of picatinny rail. Evan used a dremel tool with good success. The key here was to make sure the stock was nice and level according to the action and bit, and that my cuts would line up with the barrel. This took some doing, and I ended up mounting the stock to a piece of wood that allowed me to clamp it in the vice and true it up.
I worked nice and slow, as the machine I was using was not exactly setup for this, being a drill press and not a milling maching. I kept constantly checking for the fit of the rail, inserting the barreled action into the stock to make sure that I was on the right track. This took me a long time, but paid off.
As you can see here, I got a little overzealous on a few of the end cuts, but it wasn't a big deal because it was going to get bedded in with epoxy anyway. What's not pictured is the additional hole I drilled about an inch behind the one in the rail. I used two stainless steel maching screws to fix the rail to the stock, and then bedded the whole works with Devcon plastic steel putty. The rail is now essentially a part of the stock, it's in there rock solid. I also machined the pic rail down a litte so that the bedding area would be a little more flat. Probably wasn't super necessary, but I figured what the heck.
I finished it off be bedding the remainder of the forend. I inlayed a carbon fiber arrow the length of the barrel channel that helps to add a bit of stiffness. After it was all bedded and set up, I used a bill to make sure that the barrel was free floated.