Looking to buy a pdf armorers manual for AR15 and/or M4.. I am actually a certified M4/M16 armorer (which translates to AR15 of course) But i have forgotten so much as training has been so many year ago and all I do now is change triggers for my buddies (I am my prepper groups armorer) So I kinda dont know anymore how do to 70% of the stuff a AR15 armorer ought to be able to do. Or at least it would take me trial and error to figure out. Anyone have a link to a good online AR or M4 armorers manual? If I can just see the right pics i am sure it will all come back to me.