The reason I say this is that the jacketed bullets you mention have to be run "up to speed" to work correctly as far as expansion goes. The cast slugs don't.
Exactly. My goto bullet for the 45 Colt is the 250 XTP, but I push it a lot faster than 900 fps. You need penetration, and if the bullet does expand slightly at low velocity it isn't going to penetrate as well as a heavy cast slug would. Not saying it won't kill a deer but I don't think it is the best option in this case.
One other thing, don't rely on the velocity data posted in a manual as gospel.
