Lee tops out at .510" or so, I suspect as much for reasons of commercial demand as anything else. I've lapped them out to .519", and made similar dies (7/8x14 threads) in .579". I think .710" would have to be made on larger threaad size.

If you've got a press large enough to load cartridges taking those bullets, just make Lee-style dies to fit your thread size. In an RCBS Rockchucker, you could start with a piece of threaded rod (or a bolt) in 1-1/4x12; that should be large enough to bore and ream to size bullets to .840".