This book provides instructions on the operation and maintenance of rifles from both ArmaLite and the Eagle Arms division of ArmaLite. Read and understand it carefully before you try to use your rifle. Your safety, and that of those around you depends on your knowledge of your rifle and on your knowledge of safety rules common to all firearms.
Your second responsibility as a gun owner is security. Make sure that your rifle remains in responsible hands..Yours! Don’t become and unwitting partner in a crime or tragedy.
The entire AR10 manual is available for free here!
Additionally, I found the manual for the 5.56mm AR15 version of the M15. You can get it here.