If you would like, we would be happy to check out your lock. I don’t ever recall a Colonial frizzen rebounding in the past, but maybe you got a weak frizzen spring. Just send it in and we’ll do what is needed at no charge.Rebounding frizzen on my Kolonial will break every flint within 3 strikes.
Solution is to extend the top portion of jaw leather out onto the flint slightly. This cushions the rebound so that the frizzen heel no longer breaks the Flints.