I have read and used carbon arrows to stiffen a forend. I used a dremel with a coarse carbide cutter to make the necessary channels, reinstalled the action and make shims for either side to keep the channel centered to the barrel, removed the action, mix my epoxy, wet coat the interior of the forend, lay the arrows back in the channel, pour in the epoxy and reinstall the action with the appropriate shims in the correct locations. Wait 24hrs to cure, clean up any mess.
Be careful, it's a sprint not a dash, a little goes a long way, patience pays dividends, you can do this in multiple steps, epoxy can be recoated within a given time frame, most epoxies only need about 12hrs to set and can be recoated within 24hrs, that is the beauty of epoxy resins. Polyester resins not so much.