I know you can run as low as 4 grains of Blue Dot in a 223 with no ignition issues... and
6 grains max was a published load by Alliant in the early 80s for the Hornet....

so for a Fireball, it would be an application...

I know I did a 17 Fireball load for a friend who had one, but he has since passed away,
and that was utilizing Blue Dot... ( and NO he didn't pass from blowing up something
with the Blue Dot, he just passed being 83 years old)

I'd start at 2.5 grains of Blue Dot and work from there...

When ever I get around to getting a 17 Fireball barrel, for something, I can let you know then

or if someone has a good deal on a slightly used Rem Model 7 Predator in 17 Fireball
I could let you know after one of those fell into my hands...

"Minus the killings, Washington has one of the lowest crime rates in the Country" Marion Barry, Mayor of Wash DC

“Owning guns is not a right. If it were a right, it would be in the Constitution.” ~Alexandria Ocasio Cortez