I am trying to understand the relationship between powder burn rate and bullet weight. I am loading for a 7mm-08 22 in sporter bbl. If I understand correctly I will get better accuracy with a little slower powders with the heavier bullets and better accuracy with the lighter bullets using a faster powder. Do I have this right?

No, there is no magic formula for accuracy. What you have right is that, generally, slower powders give higher velocities to heavier bullets, and vice versa..
Not always. Depends on the bore to case expansion ratio.

What dpcd said.

In a given caliber, slower burning powders for the heavies and faster burning for the lighter pills as a general rule. Keep in mind this is a starting point, each barrel is a story unto it self. Review the available data for each powder/bullet weight, I go with the slowest burn rate that fills the case. Find this combo and give it a try, use one of the popular methods, ladder or OCW and see how it goes.

I am having good results with the Hornady 139gr pills and Varget.

Best of luck with the 7-08
Carl

i usually look at the load density of each different cartage i load. i try to stay around 90% load density. I usually stick with RL-15 or IMR 4064 with the 140's in 7mm-08, this gives me my best accuracy with velocity..

H-414/W760 gave me a little more velocity, but not as good accuracy.