I'm not sure about the SS one bu BT does stand for boat tail. Sounds like a fun time!

Good choices

These are premium bullets ideal for elk sized game and the rifles are more than enough for elk. The BT does stand for boat tail which means that the bullet maintains its velocity better than a flat based bullet over a long distance. This is not too relevent to elk hunting unless you are shooting over 400 yards. You are right on the SS. The most important thing with these bullets is to land them in the right place for a sure kill. ANY bullet you shoot out of those rifles will kill an elk if you hit it in the right place.

Both of these rifles add about 40-50 fps of velocity for each inch of barrel length. Therefore, a 26 inch barrel will accelerate your shot to nearly 80-100 fps faster than a 24 inch barrel. This would mean about 2 inches less drop at 400 yards (26.5" vs 28.5" with 100 yard zero) with the .30 caliber 180g boat tail. The best way to accommodate your specific ballistics is to practice shooting at each hundred yard increment out to about 500 yards so you know where your bullets hit and how to aim at that range. Good luck and happy hunting... wish I was going with you!