Chasing a ring is getting the back of the bow down to one continuous growth ring from end to end of the stave so that it doesn't break under tension. With whitewood staves, you can peel the bark off and you already have the unbroken ring. With heartwoods like osage, locust, and mulberry, you usually have to take off the sapwood and follow the ring you want down the back of the stave. It is simply "peeling" off growth rings until you get down to the one you want. A Holmegaard bow is a style based on an ancient bow found preserved in a peat bog in Denmark. About 1/2-3/4 of the way down the limbs, they somewhat abruptly taper to narrow, thick tips. Most of the modern variants are probably more abruptly tapered than the original. Search for "Holmegaard" on the forum, should be plenty of pics.