Interesting.
It did put me to thinking about variables at the time.
First, I've never used an overpowder wad.
Second, I'd be curious if there's such a thing as a slow lot of FFF and a fast lot of FF. It can happen with smokeless, and I'm sure it was an older can of FFF and a newer can of FF I had that day. Recipe change? Difference in ingredients?
Further, I didn't run long strings, I ran two rounds each and went on. Admittedly, not a great statistical cross section.
I didn't write down exact speeds (I gotta take better range notes) though I do remember there was right on 100fps between loads with the FF being the faster @ right on 1800fps. Those were the results from that particular day. How do I remember them? Cause I'm still shooting FF!
Remember, I was shooting 5 grains MORE FF than FFF.
Maybe I (or my chrony) was mistaken. Maybe I need to do more testing. Maybe being as how either load will put three in under and inch (often in one hole) @ 50 yards, I'm not gonna worry too much at either speed.
I will say I've meant to test it further. But I hate chronographing. I'd much rather shoot at targets and have had very little luck (like Herb) lining out both at the same time.
