I felt rip out for the past month, but still couldn't break 275. I broke it today, hitting 300 for the first time, and all I did was loosen up my body and use a much shorter (almost non-existant) reach back while still keeping my shoulders closed. This let me put all my acceleration into the last bit of my throw. Using my lace (half red and half white) I could easily notice how much faster the disc was spinning.
For me, the elusive snap doesn't feel much different, it looks different. The disc rips out at a higher velocity, faster than if I was throwing a ball, and spins much quicker. To get there, I smoothed out, simplified, found a comfortable grip (the fork), and drilled my late acceleration by simply removing most of my reachback.
Its been a month of hard work, now I know snap, and hopfully will see it out on the course again tomorrow!