My T.G. is Snakebite and he was a member of the committee that did the research on loadings and what will or will not produce enough smoke to meet the standard set by SASS for competition at State and higher events.
You can shoot a lot less than a full case load of 777 and make the standard. Although the manufacturer suggests no air space, 777 can in fact shoot CAS distances with a air space similar to smokeless powder. It is position sensitive and using mag primers helps, but the fact is, at small loads, the stuff is not very accurate, as in try to group some at 15 yards and you will see.
Then there are fillers. Breakfast foods are popular. There is foam caulking rod backer and who knows what else.
I know the current world FC champion and he goes fast, but he does it in style, as in he does not download, but does shoot .38s. When you can pile shot after shot onto close grouped targets and hit them at speed, with clouds of smoke from true BP, then you earn a lot of respect from other competitors and you know you did it the right way. Blackpowder should look like blackpowder is what I am trying to say. Wimpy wisps of near white smoke don't look like the right class and I must not be the only one thinking that, since they did come up with a standard.
The reason I am not giving you the load is because the minimum load of 777 one day will qualify and the next day the very same load won't. That would be due to weather and atmospheric conditions. When you say barely meets I think that in itself could cause you some issues if challenged on the smoke standard. Testing is done same day, same range, not by pulling bullets and checking powders or quantity.