The question I am trying to ask is something like, "Is one unit of 4F equal to 4 units of cannon powder?" Or are there charts of units of powder to projectile? Similar to what you find in loading for pistol or rifle cartridges? Thanks to anyone reading this!
No--one unit of 4F is not equal to 4 units of 1F. Those designations are not designed to directly measure burn rates or relative explosive power of each type to the other.
The F or Fg is short for "fine" or "fineness" of granulation of the powder. It is a size measurement of the granular units of powder--not to be confused with grains, which is a weight measurement.
I found this approximation of the sizes for each in one of my old books. As you can see there is a min and a max for each.
1Fg.... .047"-.063"
1 1/2Fg... .035"-.054"
2Fg... .026"-.054"
3Fg... .020"-.034"
4Fg.... .009"-.020"
Obviously, the size of the granule affects the burn rate, but I have never seen any charts designed to suggest that one substitute one granulation of black powder for another by changing the amount used---
mainly because it is unsafe--the point being that you do not want to use a fine powder with a high burn rate in a large bore.
I will repeat again that reducing the amount of this fine powder does not counter the problem because it creates additional safety issues.
One of the caveats of black powder is that you do not want excessive space in the chamber of any weapon that uses it. Fine powder creates a very large initial pressure spike, which along with excessive airspace behind the projectile tends to turn a larger bore cannon into a pipe bomb.
Black powder is a totally different proposition from smokeless. It is simply a mechanical mixture of sulfur, potassium nitrate, and charcoal. Once the right combination of those ingredients was decided on, its manufacture hasn't changed drastically for 100's of years.
On the other hand, smokeless is a complex chemical compound with wide variety of manufacturing options--thus all the reams of load data that gets published every year for hand loaders.
Users of black powder have been following the same general guidelines for many centuries for a reason and that reason is that it is simply unsafe to do otherwise.
Here's a link to a Wikipedia article on black powder. It's worth a read.
http://en.wikipedia.org/wiki/Gunpowder
Cheers