Looking at finally making a brush from moose antler that I bought. I will be initially using a 26mm mixed boar/badger from Maggard's as the knot. How far down should I initially drill for the knot. I do not have the equipment at home, but am making a special trip to a buddies place who has all the woodworking equipment. Would it be better to drill too deep and then just shim, or should I drill, do a test lather, and then drill deeper if needed?