I have one of the older Sendero SF rifles with the strange 9.25" twist barrels. It will stabilize the 180 VLD's, but I have not had a chance to load up some Berger 180 Hybrids to try them. I load using Federal 215 (magnum) primers, and H1000 powder. I am fixing to develope a load with IMR 7828 SSC and the 180 Hybrids, and will let yall know how it goes.
Best thing you can do is buy a chronograph. I haven't had the cash to buy the one I want until now. So I ordered my MagnetoSpeed V2 yeterday, and it should be here tomorrow. I might go shooting Friday to test out all the new stuff and work on some load development with the 180 Hybrids.