Well, I have beat myself up plenty over the animal getting away, this is the 1st animal that I have lost in about 40 years and only 1 of 2 I have had to look for over 10 minutes after the shot to find, and that adds up to well over 100 hundred successful harvests from 80 lb whitetails to 900 lb elk. I have several rifles from 458 Cal to 17 Cal, each has its best use area. I develop loads for each and every one of them and all of them are tack drivers nothing I own, with exception to a 7.62x39 and a 458 SOCOM shoots more than .5 MOA at 100 and 3 shoot 1 tiny hole at 100 consistently. The reason I use the Grendel is due to the fact that, up until 4 years ago when I got the Grendel I used a 225 Winchester Model 670 with a 55 Gr Sierra pill to harvest the whitetail, smaller exotics, hogs etc., exclusively and have since I got the rifle when I was 12 years old from my old man, that was 1969. The Grendel added 65 Gr of projectile, about the same or less recoil than the 225 and was a little bit more accurate and held up better ballistically on longer shots.
When I have either of those 2 rifles or my 257 Bee in my hands there is no doubt about what the end result is going to be, until Monday afternoon.
My original post was not seeking advice, I know where all the kill zones are located on almost every 4-legged animal on the North American continent and several from Africa and Asia. My post was to vent about losing a viable game animal, with a shot placement that has been 100% effective until now. Maybe a heart lung shot would have dropped him right there but then again, I've helped look for animals shot in that kill zone and never found them, so nothing is certain 100% of the time.
I thank you all for your comments and laments, woulda, coulda, shoulda is all that I have, I would really rather be bragging on how good that back strap is.
Another big animal will come into range again this year and following years to come I hope, and I am cautiously certain of what the end results will be.