For most guns, lengthening the pin holes in the lugs so that they are 1/2 the pin diameter longer both front, and back, is enough for expansion. Don't deepen the holes in the lug, as that introduces slop into the barrel/mortise fit. Just widen the holes to allow the wood to expand and contract as needed. ( In cold, dry weather, wood tends to contract- in warm, humid conditions it tends to expand.) :thumbsup: