Browning Auto 5 16 gauge shotgun
 

I have acquired this shotgun. It's serial number is A15XXX. I need some help in understanding how to set up the friction ring for heavy and light loads. I am not all that familiar with shotguns so I need some assistance. first of all what is a heavy load? What is a light load? Is setting for one of them better if I don't know which I will be using? What are the advatages of each? The instruction is not clear on which way the bevel of the friction ring is placed.
Can anyone give me explicit instruction preferable with a diagram on how to assemble them?
Thank you very much for your help.