I had been shooting FF Swiss earlier in the day 'Swampman' but tried the F on a whim and was pleased.  BUT, your so right about the fouling.  AWEFUL!!!
I was just interested if it would work.  On the Swiss site, they do list F for patched round ball in calibers ABOVE.58.  I don;t plan of making this a habit, but it shot quite well with the single F.
I think going forward that the Zouave may just be my go-to rifle for our club shoots.  Sorry TC Hawkin, looks like your staying home for a bit! 
