Becky locks are no longer available from any of the suppliers. Your only chance is finding someone’s who still has one and wants to sell. Haven’t been made in some years. Parts are also almost nonexistent.
I took an old .22 Rimfire barrel and made a muzzle loader out of it to teach the kids in our firearms safety course. It shoots 30 grain air rifle slugs into 1/2" at 25 yards and will go thru a 3/4" pine board with 5 grains of 4f. I tried using a .220 round ball and patch with this gun, but found it too hard to handle those tiny balls with my sausage fingers. The slugs shoot great and are somewhat easier to handle.
Found a Becky lock!
I had a friend who used an old .22lr barrel to build a muzzle loader. He used buckshot, I forget the size, loaded bare in it. It was a very effective squirrel getter. And, he was a meat hunter, would not have used it if it didn't work.
