I'd be very careful about using a pistol powder in the '06 cases for fire forming. Personally I wouldn't do it and would opt for a light load of the rifle powder of choice.
Now, THATis not a good idea.... There's not enough weight ahead of the powder to get a good burn when you use rifle powders.... There IS for pistol powders though.... I don't think you've done much of what your suggesting....
I can't tell you how many thousand rounds of brass i've fireformed as i described above, and that's the way it was always done for many years, and it still works...
I would think folks reading this have brains enough to NOT USE A BULLET on top of the pistol powder...
Useing a tapered expanding ball works, it's just won't always give you necks that are the same thickness all around...
DM