To dimple the counter balance rib for a size 10 wood screw I used a wood screw counter sink. First I drilled the countersink shape into a hard piece of Oak wood and used it as the female dimple. Then I used the screw itself as the male dimple and I hit it with the rivet gun using the flush head. It pounded the dimple in the rib, just the right shape. Then I used the same wood countersink and drilled into the lead weight and made the countersink holes that will except the dimple. Worked just fine. Prior to this I did mess around with my dimples, and countersink bits from Avery's but none were the right shape. The wood countersink bit is available at hardware stores.
Created the female dimple die in Oak
Used screw and hit it with rivet gun to dimple rib
