It's happened on my hand also. But with a few of my other pipes as well I've noticed. I take a guess and say it's some of the excess stain heating up when you smoke. It should go away though as you smoke it. Since it's a Boswell pipe, give them a call and ask. There's no such thing as a dumb question. I'm sure Dan or JM could give you an answer about what's happening. Maybe even take a soft paper towel or cloth and wipe it down. Just be careful not to damage the briar with a cloth too rough for it.