I have been contemplating using the progeressive to load 308 for my M14. It is a hungry thing and I can't seem to keep ahead of it with a single stage.
I used to load with a RCBS Powder Pro and automatic powder dispenser, one charge at a time in a loading block. It worked well, but took about 30-45 seconds a charge.
To speed that up I would take a Lee dipper (never have used those, just got them with dies sets) and add a scoop or two to get the bulk of the powder there and let the digital powder dispenser top it off.
Another problem with that pre chargemaster system is when loading for a big case, I couldn't get it to drop charges over 100 grains. So, I'd throw a 11 grain charge, rezero with that charge sitting and set it to drop 100 grns. Check that in a beam scale and good to go.