I currently have my new mp15 sport decked out with a vortex strikefire and it is nice. However the new range I joined has 200 and 300 yard targets that I would like to be able to shoot but is to difficult. So I'm thinking about getting a scope and switching back and forth between it and the red dot. Since the rails are numbered it should be right on the mark if I switch back and forth right? I've seen quick release mounts for scopes can I buy something similiar for my strikefire

Also do you have any scope recommendations? What kind of mount do I need to deal with the front sight? I currently ha e the red dot set up for cowitnessing with the iron sights