Klik recommends a good bullet with the Speer Unicor, and Beretz is correct with the velocity.
I've run 300 grain bullets at 2200 fps, and now run them about 1800 out of my .45-70 (if I use them, I tend to use a hardcast nowadays), and haven't really noticed anything dying any slower.
As a matter of fact, the Hornady 300 grain HPs keep their integrity much better at the slower speed. The upper threshold for them seems to be around 1900 or so fps.
