9 is on the edge. Have to try it to find out. I have a buddy that speficially shoots 9s with 80 sierras. But he is on the edge a bit too of stabilization but that comes from his BR days.
What I can say, pick the shortest/fattest 80.. and run it as hard as you safely can.
Then if its a true 9 you should be fine. 2800 fps from a 20 inch tube minimum.
Be aware that not all barrels are true and if its leaning towards 10 instead of leaning towards 8 you may not have any luck.
I'd suggest you put up a quest for someone with a bunch of 80 sierras to sell you about 20-50 of them just to see. Then you will know.
If not there are a passle of 75ish ones. But be aware I"ve often thought the 77 sierra harder to stabilize by a tiny bit than the 80, due to bearing surfaces not allowing as much speeed when set to mag length safely... so even though its about the same as an 80, the 80 might work and the 77s not... 75 and 73s should be easy though.
