I had to get more info on FFFg Triple 7
Rod's comments on the stuff on Hodgdon's website were very useful and without trying to put words in his mouth, it appears he and I both were suffering from the same minor lack of understanding because of some ambiguities.
When I loaded those .45 LC rounds with what was 35 grains of Triple 7 FFFg, I came back from the range with some fairly stunning results which I mentioned on the forum at the time (Probly 18 months ago.)
Several forum members cautioned me that the rounds were likely unsafe because they had the potential to develop too much pressure. They spoke of warning on the label of the canister which addressed Triple 7 FFFg in cartridges being dangerous because of the over pressure potential. I looked at my canister (which I no longer have). It stated that FFFg was not intended for use in cartridges but it did not say anything about over pressure, or danger, or the end of the world as we know it.
I took the guys at their word and downloaded most of the FFFg cartridges. But at the same time I put a call in to the Hodgdon Tech support folks. I got hold of a guy who appeared to be a little under-briefed on black powder and subs but he did confirm that the reason to avoid FFFg in cartridges had to do with over pressure and the creation of a dangerous situation.
Rod gave us the caution from the Hodgdon site which I was unable to find 18 months ago but see it very clearly now. I read it. It created some questions and so I called Hodgdon again. This time I spoke with a guy whl also needed a little help with BP and subs but he was at least willing to own what he said.
His words:
Triple 7 FFFg is never to be used in cartridges because of the danger created by the over pressure situation.
Hodgdon recommends against granular fillers of any kind because of the possibility that the filler will settle (remember, Hodgdon recommend only light compression) leaving an air gap.
The Hodgdon caution says
Cartridge loads should be used exactly as listed in this pamphlet. You may safely use a card or polyethylene wad up to .030" in thickness to protect the base of the bullet. Loading density should be 100% with light compression not to exceed .100"
To me this means that you can't change the load of Triple 7 FFg in a cartridge. I asked that question to the Tech guy and he confirmed that you should not lighten the load because there is no way to fill the gap between the top of the powder and the bottom of the bullet.
(Maximum .03 wad, maximum .1 inch compression.) Only way to reduce the powder charge is to use a longer bullet or reduce COAL. So even my 28 grain .45LCs with filler should be pulled apart.
I went on to ask the guy about compression. He confirmed that the best performance of Triple 7 FFg or FFFg is when the pullet just rests on top of the powder so as to avoid an air gap. He recommended a maximum compression of .1 inch.
He said Pyrodex should not be compressed more than 1/8th inch with best being 1/16th.
Pyrodex can be loaded at less than full capacity as long as the air gap is not filled with granular filler. Has to be a solid wad.
This information was retrieved from the Tech Service number at Hodgdon from a guy named Mike at 11:20 today.