Intoodeep,
I'm off today, so when I saw Marine Dad's post, I went digging to see if I still had the original instruction pamphlet from my CVA Nap. III, and lo and behold I found it (unbelievable- pack rat). Now mine gives different recommended charges than yours, this booklet is "Copyrighted 1976 Connecticut Valley Arms, Inc.," and it lists the starting load as 50 gr. of 1f or 2f, and the Maximum load as 70 gr. of 1f or 2f. This discrepancy in amounts probably goes a long way in showcasing CVA's ?brilliance? in trying to guard themselves against legal actions.
Anyhows, Marine Dad, I just snatched this whole from anothr BP site, and this is basically what I was told by my father, uncles and other experienced BP shooters when I was coming up.
"The short answer is to adhere to the manufacturer's recommendation for maximum load for your particular muzzleloader. However, this information is not always readily available. From a practical standpoint this becomes a moot question. Increasing the powder charge to near maximum levels will lead to diminishing returns on the efficiency of the load, as you will experience significant increases in pressure with only marginal gains in velocity with an adverse effect on accuracy. As a general rule, a good target load can be established by starting with a grain weight charge equal to rifle's caliber ( eg 50 grains of FFG for a 50 caliber rifle). To find an efficient hunting charge, increase the charge in 5 grain increments to the point where accuracy is acceptable for your hunting situation. Generally, this should be limited to 30 percent greater than the most efficient target load."
This is what I still go by for a bore of .75 caliber or under, and that's why on the other thread I said Max. 100gr. of FFg with a patched .69 lead ball, or 150 gr. for a salute loaded with a light wad; so as Kabar said, using the mean of 70 gr. of FFg you can find the most accurate load for your barrel experimenting within the range of loading down to 50 grains of 2f, or up to 100 grains of 2f. Don't misunderstand what I'm going to say now; I'm not suggesting to load it over 100 gr. when firing ball, but these barrels are made of mild steel (I don't know what the European designation would be, but here this would be called gun steel, or 4140, so they're tough, well made barrels.