Interesting reading:
Don't know if you're better off with that long throat or not. The 308 I just started using/testing has an extremely short/tight throat. Can't use a lot of the bullet molds I have because the noses cast too large with a hard alloy. The end result is the base of the bullet is waaaayyyyy down in the boiler room of the 308 cartridge.
I see you're age hardening your bullets. Just started doing a test with using the same alloy to cast 2 batches of bullets. The 1st batch that I cast last week was water dropped and will be age hardened. The 2nd batch that I will cast next week out of the same alloy will also be water dropped. But the 2nd batch will also be heat treated. The end result is:
aged hardened vs heat treated/hardened
30 days vs 7 days
I've never heat treated any bullets before, actually I've only heated/annealed cores for swaging jacketed bullets. Don't know what to expect but there's only 1 way to find out. Perhaps you could do a little testing in the future with age hardening vs heat treated?