I've been using the 7828 ssc for my 30-378 because it feeds faster out of my RCBS electronic.
102.4 grains is max behind my 190 gr.SBt's causes a light case shine. So it's the max I would ever use. I use Retumbo, R-25, and now A8700 for my 220 and 240's.
I've only had time to load up and shoot about 100 rounds to get ready for elk season. I did not do chrono time yet. I just went for what was max and then back it down a hair and worked on accuracy on the range. The length was right what the books said after i did all my bullet seating depths.
.270 Ackley improved 29 inch 1.250 dia. target barrel 7mm STW 28 inch 1.250 target barrel. I also love my .458 mag for varmints and the biggest game in the world.