Dan- that's the way I got to be with FFG until I got the .45- then tried 3F first.
The only thing I have against using 2F in the .40 and .45, is about every 8 shots or so, I get a hard piece of fouling plugging the vent and have to prick the vent. Of course, if using it for hunting, I'd prick the vent every time it was loaded so the flash in the pan wouldn't happen. this fouling might be coming off the scraper side (vent cover) of the frizzen, or from the inside, which I doubt due to the gasses venting out the vent under pressure.