antioch11: The 150 grain SST works very well on mule deer out to 300+ yards.
I haven’t taken an elk with an SST yet. I surely would not hesitate to put one in an elk to see the out come. The SST shoots well and stays together well from my experience.
I used 162 grain Hornady bullets yesterday for iron sights shooting at 50 yards, the result was an impressive three-quarter of an inch group. These are great rounds, they're more expensive than Remington Core-Lokt, but I think the ballistics are better.
Try to put your tree stand in a tree with plenty of background cover, keep the prevailing winds for that time of the year to your face, and take care of those pesky squeaks and creaks your stand may have developed while sitting in the shed. A good treestand lube can be made by heating petroleum jelly until it reaches a liquid form. Some hunters have reported success by including a cover scent in this mixture before applying it to their stands.