I cant speak from experience, because I have never went after a grizzly before. I have no doubt that a 7mag will get the job if you use a well constructed bullet and you put the bullet in the proper place. That being said if you dont put it in the proper place and get into a tight area with a P O grizzly I'm not sure the 7mag has the bone crushing power to cease hostilities. No telling how many grizzlies have fallen to the old 30-06, so the 7mag has the power, proper bullet placement is the key.