Horn Striker Block Used to release tension on the mainspring when putting guns away after shooting. With the gun apart, place the striker block over the firing pin holes, pull the trigger(s), and the horn is the perfect medium to absorb the firing pin fall. This procedure will insure that firing pins are not fractured. Curved on both ends on the back side to fit easily into the palm of the hand. Highly polished Buffalo horn, 2 ¹/8" x 1 ³/8".