FWIW,
I've got an old CVA St. Louis Hawken .50 I've had since I was 16.
For years the load was 85grn. FFF, Ox-Yoke Patch, Speer .490 ball. I always figured 85 of FFF would give more speed than 90grn. FF, plus, it would never shoot worth a hoot with FF and Ox-Yoke patches, which I used for years.
Bout two years ago I ran out of Ox-Yoke patches, so I bought some pillow ticking and smeared bore butter on them. I tried FF again and it shot as well as FFF. Then, I broke out the Chrony, the FF (90grn) load ran 1800fps. The FFF (85grn) load only ran 1700fps. Not that 100fps is a big deal, but it did fly in the face of what I had assumed to be true for the better part of 25 years.
It also taught me that the patch do make a difference!

Last edited by Potsy; 10/29/13.