We may all be right, and wrong at the same time!
I learned something tonight by talking to Pete at home, where I could ask him to actually look at his Swiss 1 1/2 powder, and compare it to his Goex 2Fg powder.
Apparently, Swiss has changed its numbering system for sales in America, to try to end the confusion it has caused here. [ I wish they also corrected the website!]
NOW, Swiss 1 1/2 is between Fg and FFg Goex in granule sizing. It is coarser( meaning larger in size)than Goex FFg powder.
What makes it put more powder into that volume measure is the fact that the Swiss POLISH the granules, and in that process, make the surfaces SMOOTHER, and remove edges and corners to make the granules more ROUND.
My brothers 70 grain volume measure, using Goex powder, throws 75.2 grains of his new Swiss 1 1/2F powder. That is an increase[difference] of only 7.4% of the total volume- not much when using black powder to propel anything. The polishing of that the Swiss makers do does make the powder flow more easily thru measures, and the roundness allows the powder to compact tighter, even tho the individual granules are larger than Goex FFg.
Mike Brooks is correct about the roundness being the major factor.
Once again I get to apologize for the confusion I caused here.
:surrender: :shocked2: :idunno: :hatsoff: