For loading the big bores I only use a RCBS A-2 single stage press, it will load them all including 50 BMG..Its a great press with lots of room to work in...

I made an adapter that attaches to the handle of my trimmers that hooks up to a drill press, speedy is the word...

On the big bores however, as I crimp them all, I buy a set of file trim dies in each caliber so that my crimp will always be exact for each case loaded..Automated trimmers are grosley inaccurate IMO...