Flatten a lead ball with a hammer, or stone, and you have your flint wrap. It needs to be thin to wrap around the flint, and you can trim it to the width of your jaws. Eventually, it will weigh less than 20 grains( less than half the weight of your RB), so don't be afraid to trim off "wings", or any lead that sticks out beyond the jaws.
The ADVANTAGE of using lead, over leather as a flint wrap is twofold: the lead will form to the smooth but uneven surface of the lead; and it will NOT let the stone MOVE in the jaws on impact with the flint. Instead, you get a clean even stroke of the flint along the face of the frizzen and a shower of sparks thrown into the pan.
Leather, no matter how thin, or dried, tends to become a shock absorber, and allows the flint to rebound on impact, causing bits of steel to become clogs in the edge, and prevent a good stroke, and slicing of steel from the frizzen. Eventually, the clogs prevent the flint from cutting steel at all, and you have a misfire.
If the lock Geometry is at all wrong with your lock, the problems are compounded. All this leads to frustration by the shooter, a distrust as to the reliability of ignition from flintlocks in general, and finally, selling the gun to buy a percussion gun instead.
Up under Member Resources, you will find a section, " Articles, Charts and Links". There are a number of very good articles there you should read. One of them is about shooting and tuning flintlocks. It will help you check your lock geometry on any lock, and teach you how to correct the problems that faulty geometry create.
If you have any questions, please feel free to send me a PT, and I will help you "fix" your lock. :thumbsup: