Effective range is whatever your effective range is. You can't strech range if you can't shoot. Your practice range and the amount of practice is what will determine the effecitive range of any caliber. There is nothing that will work if you don't make it. HAPPY HUNTING
I agree 100%. Just because you have the tool that can do the job, doesn't mean you can. Most often, the shooter is the weak link in making a good shot at distances over about 300 yards. Unfortunately too many will just take pot shots anyway and end up with a wounded and lost animal. Know your rifle and the ballistics of the ammo you will be taking. Put some time behind the gun and not from the bench, from positions you expect to be taking a shot from in the field. And finally, make sure you have good shooting technique such as breathing, trigger squeeze and sight picture to name a few. When you practice, don't be afraid to get a recoil pad such as this
PAST. It will allow you to practice with out developing bad habits due to recoil (esp when shooting a fair amount of rounds).
