150 grain expanding will do. Your choice. Unless things have changed recently, deer are not armored. I don't shoot factory ammo because I reload, but I really don't see why you need to spend a lot of $$ on special ammo when some Remington core-lok't will do. I wonder how many deer have been harvested with the core-lok't and the old silvertips over the years? Sometimes, it it ain't broke, don't fix it.