it should be OK on elk if you used maybe like the 178 class bullets. But elk are so damn big that maybe like a 20 inch 300 PRC or 6.5 PRC with the Barnes bullets would be better.
You can always just use a Barnes bullet like the TTSX. it will never let you down. Goes in the animal .308 and comes out the other side the size of a quarter no matter what animal. :)
In my 6.8 spc i use the 110 grain barnes TTX bullet and it kills all hogs and the puny FL deer awesome in a 7lbs rifle. Perfect for me. 2600 fps from short barrel
Never only 1/4 inch of the flasher sticks out the edge. Place them on the top side of target and all the splatter goes down away from them. Especially at one mile