RE: FFG or FFFG in T/C Omega?
You will see a LARGE drop off in power with APP compared to BM3. BM3 is a little more powerful than 777 and APP is quite alot less than 777. I would say you would have to use, at least, 15% more APP to be equal your load of BM3, up to a max of 150 grs.
I didn't have very good accuracy,in my Omega, with APP (Jim Shockies Gold). It is very clean and seems to actually load easier and shoot more accurately with a fouled bore (no cleaning between shots).