As was indicated by most posts here , the only way you"ll know for certain is to do your own expermenting . I usually use 3f in all my guns , both caplock and flint and also use 3f for the prime . So far , none of my guns seem to do a great deal better with 2f ? I only have one smoothbore , it has a short barrel and does well with the 3f as well. There is little doubt that a smoothbore with a long barrel might do better with a 2f main charge ? :idunno: :hmm: