I have a question that I cannot seem to find the answer. On the stock below where the Red Dot Scope is mounted, there is a dial. From what I have found so far, I think this is the Dial-A-Range® trajectory compensator. Is this only used if you do not have aRed Dot Scope or will I use this in conjunction with the Red Dot? If anyone could fill me in or point me to a website that explains it I would certainly appreciate it.