This has been a frustration and trial and error process for me also.
Using my Temco TH0005 hydraulic for 2/0 cables and lugs ... I had to actually go down to a 2 gauge die in order to get the crimp I wanted.
I don't know if that is because of inconsistency in in Temco dies or what.
I have had way fewer problems with the hydraulic crimper than with much smaller gauge stuff. With only one gauge of wire did I have to use a smaller die from the TEMCo kit than the wire gauge. I asked TEMCo about that and their response was that there isn't a consistent reference for cables. That seemed a bit odd to me, but I guess 2 gauge from one manufacturer isn't exactly the same as 2 gauge from another manufacturer. But in this case, I was using TEMCo wire!
I've said this before: If I had know how easy it was to crimp large gauge wire, I would have bought the equipment years ago.