Chuck,
I have nothing against the folks who provide the barrel inletting services. They make it possible for many gunmakers to make a profit and those who have been mentioned here are fine people who have earned superb reputations. But before you decide to send that blank off, ask yourself the question "why am I hiring somebody to do this job for me?" You will learn a lot more about gunmaking by doing one yourself.
If you are a hobby gunmaker, as I am, the letting in of a barrel is the beginning of a great adventure, not a necessary task that can be contracted out without diluting the pride of authorship for the finished product. It takes about 2 to 3 hours per foot to let in a swamped octagon barrel. You need a small back saw with the set ground off the teeth, a few chisels, a mallet and a set of scrapers that you can make yourself from old files or sabersaw blades. It is not that hard to do, there is guidance on how to do it in the books that most folks who pursue this craft own. So make sure you know why.
Just the meanderings of a tortured mind.
Best Regards,
John Cholin