I looked everywhere for one when I got my .270 from Kirby, and settled on this one,
Cabela's Bullet Proof One Black-Powder Rifle Case
THe only thing I have an issue with is the gasket seal around the edge. Other than that, it has worked out great holding the rifle very secure. It will also hold one scoped and an open sighted rifle depending upon how you situate them. I can also fit my .270 AM and my Ruger Compact in it at the same time as well.
It takes up a bit of room but for what generally rides in it I don't mind, as I know it will be safe.