Sierra, huh? I have fired those from a Savage 23B bolt action, over H4198 if I recall. The problem with that gun is they load too long for the mag. Single round only, and no advantage over Speer's 75 designed for the 25-20. Those Sierras are HP spitzer, and as Mr. O'Heir says no go in a tube mag.
If you're bound and determined and willing to fire single rounds, look up H4198 data on Hodgdon. As I recall, the Speer and Sierra gave about the same velocity with the same charge of H4198. But I quickly sent the Sierras to 257 Roberts duty. You'd do better to get some of the Speer. They tested in a modern Marlin '94, and those bullets are safe in a tube.