+1 on Larry Gibson.
Modern powders burning cleaner?
The dirtiest powder on my shelf is A No. 2 I get much more unburned powder granules than with Bullseye or Unique.
That said:
Shake those unburned kernels out on a piece of white paper and take a close look at them with an 8 to 10x glass. You will find that many of them are not "unburned" but just a powder granule shaped husk of ash.
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