Holy cow. Wishunter, don't feel bad. Often on this forum when asking for info, unsolicited advice is given instead. You learn to accept it in time lol.
Here it is, talking slowly. He wants light, fast bullets for varmints. Also heavier bullets for deer. Many calibers were sold on a dual role basis. He doesn't want to buy multiple rifles or get a different rifle or upper. I see no reason a little lighter bullet with a good shape wouldn't be great in a Grendel. Unfortunately that bullet isn't available yet. Just like people shoot 75 gr rockets out of 25-06's, and all sorts of other stuff.