Practicing light load without ball?

[Johnny Tremain]

some may say it is a waste of powder

Shooting is never a waste of powder.
Dont believe in light loads, only what your going to shoot for real.

While you are wasting powder, you are also figuring out how to clean, and make shots one after another.

Id spend a day in the rain shooting over faking in the basement.

 

[Brazos John]

My pan primer dispenses 3 grains of powder, thereabouts, if that helps.
When the Texas Army fires salutes, I use 80-90 grains of 2 or 3 F. Lots of flame and smoke, no recoil.
Best wishes with your research.

 

[wiscoaster]

....

Id spend a day in the rain shooting over faking in the basement.

I'd spend a day faking it in the basement over the police showing up, being arrested, and spending a day in the police station trying to convince them why I wasn't in violation of the city's ordinance against discharging firearms within city limits.