not hard to get.. took me almost two years to go from 500 to 675-680.
pretty much start training westside... LOVE to pull.. and eat your face off. IT's doable as a natty but you've got to be built to pull and have the DRIVE to have big pulls.
a good indicator.. if you can pull 635 3 times... you're probably good for 660. until then.. keep plugging away. Find exercise that work for you just like benching and have at it. I do alot of heavy rack pulls, pulls against bands, deficiet(sp) pulls, and reverse band pulls. Fidn out what your weak points are and attack them! unless you temper the weaker links in the chain..they'll always be just htat.. the weak links
I never bothered a whole lot with bands aside from here-and-there workouts with a couple buddies who use them. I stuck mostly with a shit ton of rack pulls from various positions and static holds for anywhere from 10 to 90 secs, depending on the weight. Also avoided the temptation to use straps, and just tried to gut it out with a lot of patience until my grip could catch up with everything else (though, as is it the case with pretty much every other human being, the grip never quite catches up).
Looking back, I wish I had been "smarter" and more "scientific" (i.e., using a WSB template or hybrid thereof), instead of relying on brute strength, trying to imitate the great Paul Anderson, Hepburn and others in their relative "simplicity."