CONGRATS o2bwest! Great hunt gentlemen! When I got my ram, he took two 225g Nosler Accubonds from my 338 Lapua behind the shoulder at 325yards to put him down. Very tough amazing animals. I'm surprised that little 6.5 could do it! Oh, I've stepped in it now! Just kidding!
Years of talking to guys that have hunted a lot of these animals has convinced me that they are going to run regardless of what you shoot them with. My plan was to break the shoulder and penetrate. We did that with both rams and they both died with 50 yards of where we shot them. I think shot placement is more important than caliber with these guys.