I've used Smooth On epoxy to bond solid 5/16" orange fiberglass driveway markers inside larger diameter aluminum arrow shafts. I make sure there are no dry spots without epoxy between them.
I know they can take almost anything, like being shot from an 85 lb compound bow into (and through one side of) block walls. Can't imagine breaking one by hand, and the outer aluminum shaft wouldn't scratch or wear the muzzle. If I ever break or bend a ramrod, I'll try one of these.