My thoughts and impressions
I am no expert at this by any stretch of the imagination but here is what I have surmised form making my own powder. I have tried it in both cartridge and ML rifles. I have tried corned and non corned in the BPCR. I have only tried non corned in the MLs.
In the BPCR the corned powder gave significantly higher velocities and better groups although the non corned powder was good enough for hunting out to 100yds or so.
I tried the non corned powder in a 40 cal ML, a 58 cal Enfield Musket and a 58 cal Hawken Rifle. In the 40 the accuracy was very good at 50 yds but the sound and recoil indicated that it wasn't on a par with store bought powder but more that adequate for small game.
In the Enfield accuracy was terrible and the report was very hollow sounding and recoil was non existent. More powder did not improve anything.
In the Hawken accuracy would be acceptable for hunting but the report and recoil indicated considerably less velocity than Swiss. The boolit strike on the target at 100yds was considerably lower than the Swiss powder even with considerably more powder being used.
The corned powder weighs about 6% to 8% more per volume than the non corned but the initial velocities that I took indicate about 15% to 20% more velocity for the same volume of powder.
Sunday evening I shot some of the corned powder in my BPCR again getting ready for deer season coming up. I shot some Swiss as well as the corned powder and the Swiss shot into the same group as my corned at 100yds. The group for 12 rounds was only about 4". I have shot better groups than that with the corned powder but I threw those rounds together in a hurry and I think that the loading might be responsible for the group size. It is still good enough for a deer at that distance but I'm expecting improvement, as my process is refined.
In conclusion I really have fun making my own powder and testing it and will probably continue doing it although for competition right now I will go with a known entity.
For sure this is not a scientific test, just my impressions at this point.
Bob