been there done that... you gotta knock 'em out with a dewey rod... lookin' like a frontiersman loading his musket out there... embarrassing, sort of.
You said Hornady was wanting to help... they need to measure the case head diameter of their brass. It's about .002" TOO SMALL, and the Savage extractor can miss the rim at times. You can put the same spent shell back in the chamber and it'll still not extract (but tilt the muzzle up and the case falls out)...
Savage can send you a new extractor. If you adequately describe your problem to them they'll understand what's going on (if you get the right tech) and you'll get a new extractor, spring and ball in the mail.
Compare the Lapua brand rims to the Hornady rims and you'll see the .002" difference. Small amount of difference, yes, but enough to cause the Savage extractor to miss the rim sometimes.
I have never had a Lapua brand case do this in my rifle, for what it's worth. Savage did send me a new extractor, but I have not installed it since switching to Lapua brass fixed my issue.
Dan
that's the answer... the Hornady cases are a bit small in the rim... Savage is sending out new extractors of you call and ask them nicely... but the brass is more the issue--it's not so much the rifle, as these guns work fine with Lapua brass.