Funny! I was getting my turkey pack together just today and came across a plastic police type dog whistle and thought, hmmm I should throw that in my pack in case I get hurt and people are looking for me.
Elknut app is the best. You can listen to real elk, and Paul make the calls. Then record yourself and listen to it back. This is invaluable because to me, I sound different live or listening back from a recording.
If you or someone you know reloads, Powder Valley has these bullets on sale,
Hornady SST Bullets 0.308 (300 Savage) 150 Grain Polymer Tipped Box of 100