Been there ,done that. I prefer the Barnes over the Nosler e-Tips. I have not tried hornady GMx yet.Your 270 is really not the best choice for Elk. I really would suggest that you consider getting a Magnum caliber, one of the short Magnum calibers work well. I am seriously opposed to a wounded animal and if you are not loading the 270 with a premium bullet it is my feeling that it is not sufficient. The Elk has a thick skin and heavy bones, select only partitioned bullets, bonded core bullets or solids like the Barnes or the Nosler E-Tip. I have seen the cheaper bullets come apart and leave an animal wounded and suffering. Please remember that you will be shooting at an animal that will be 500 lbs or larger.