Remember that bullet weight is almost irrelevant, length is what you care about when talking stability.
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgiLook up the lengths on the left if you need to, then plug in your specifics.
I've been using 77gr Nosler CC's for a long time in a few different 9-twist bolt guns. I'm not keen on running nuclear velocities in anything, and they stabilize perfectly fine.
Remember that the link is an idea, not a fact. Barrel smoothness will play a role in this.
Also velocity decay happens quickly, but rotational is very slow. So bullet will "Gain" stability as they travel down range.