When repairing a break at the pistol grip, what should be added for strength besides epoxy?

Adding a birch dowel coated with epoxy is the best choice for reinforcing the repair of a break at the pistol grip. The birch dowel serves as an internal reinforcement that enhances the structural integrity of the repair. When used in conjunction with epoxy, it provides a strong bond and helps to distribute stress along the break line, preventing future failures.

The dowel's wood grain and density make it a suitable candidate for this repair, as birch is a hardwood known for its strength and durability. When coated with epoxy, the dowel is securely held in place, creating a long-lasting repair. This method takes advantage of both the adhesive properties of epoxy and the physical strength of the wood dowel, resulting in a more robust solution than using epoxy alone.

The other options, while they may have merit, do not offer the same level of reinforcement as the dowel. For example, a wood block may not fit well in the break or distribute stress appropriately, while a metal pin, though strong, may not bond as well with wood unless correctly installed. Lastly, relying solely on additional epoxy does not provide any structural support, making it a less effective choice for ensuring a strong repair.