All the bullets you listed should work fine and dandy on elk...
Back when I didn't hunt big game many a moon ago, I put in for and received a coveted Michigan elk tag. To make a long story short, I took a huge bodied bull(no mountains to climb and corn fields to raid at night) with a Hornady Light Mag 139gr SP out of my .280 with a 26" barrel. The distance was only about 100yds. Bullet ended up under the offside hide.
The point of this is if a SCREAMING 139gr. bullet of .284 can easily punch through both lungs of an elk, ANY of those 6.5 bullets with a higher SD and at a more modest velocity should punch through better. I wouldn't hesitate to use my 6.5x55 for elk if I couldn't pull the bowstring back.
