RE: Loose Pyrodex vs. Pellets
The accuracy with 150 grains of Pyrodex pellets was very good - but only with a couple of bullet/sabot combinations. The Barnes Expander MZ and the T/C Shockwave both shot well with three 50 gr. pellets.
Its the 150 grains of loose Pyrodex that doesn't seem to burn as consistently or efficiently. And the test with 130 grains seems to suggest that, as the charge comes down, the loose powder gets better.
I was always of the understanding that pellets were the way to go when you are loading above 120 grain charges. The hole through the middle of the pellet allows for more complete ignition without substantially changing the burning rate of the powder. I still think this is true - just a matter of degree.