I don't know anything about the Aussie pistol powders. Some of the pistol powders we have on this side of the world, are position insensitive - doesn't matter where they are in the case, they work. That is for the VERY fast powders - usually.

As the burning rate decreases, they must be in contact with the primer and therefore fillers must be used. Word of caution about fillers, they must fill the space between the powder and the bullet so there is no shifting, sifting, or other problems to develop.

A soft lube will probably work for light loads only - as long as it doesn't get runny with high temps. Beeswax is normally used to stiffen the mix. I've never made up any elaborate lubes before - I haven't needed them. for my rifle loads, I've used either the nromal 50/50 Alox/Beeswax commercial lube, or LBT Blue. Teh LBT took over when the comercial standard, failed due to too soft a bullet or too high a speed. With Blue, I was able to make 2,800fps (hardened and tempered WW) with a 275gr. cast bullet in a .375H&H without leading and with descent accuracy - at those speeds, it is the only game(lube) I know of that will work.

The bullets were oven hardened to approximately Brinel 34 (10F lower than slumping), then tempered to about Brinel 22.

Bullet hardness is matched closely with load pressure. You need a bullet that only "Just" becomes ductile at the pressure you are shooting. I was merely fishing in the dark and ran into success through experimentation.