Can someone tell me te rule of thumb (if there is one) for which bullet weights work with which rate of twist.  Specifically:

1 in 8"
1 in 10"
1 in 12"

Heavier works better with 1 in XX, lighter works better with 1 in XX....that sort of thing.

Thanks!!

[url]http://www.ammo-oracle.com/#twists[/url]

Faster twists are needed with longer (not necessarily heavier) bullets.  Light bullets will work well in a fast twist as long as you're satisfied with 1/2 MOA accuracy.  For benchrest accuracy, there are advantages to light bullets with slow twists, but the effects are only significant when you're approaching 1/10 MOA.  Generally the Sierra 69 and 77 and the Hornady 75 BTHP will work well with 1:9, and the 80 with 1:8, while the Hornady 75 A-Max needs 1:7.7 and the JLK 90 needs 1:6.5.

My experience with 75gr Black Hills in a 1/9" was that it shot much worse than the 69gr.  No keyholes, but 3" vs. 1" for 69gr & 52gr.