This was a comic given to troops when rifle was first issued in Vietnam war the info is still mostly correct.  Somethings that I would note: 1. I wouldn't put any lube on your magazine springs at all, it isn't needed.  2 At the time this was published (Vietnam era) they were using 20 round magazines as 30 round magazines weren't widely used.  With any ar15 magazine its always a good idea to leave 1-2 rounds out of the magazine, as it can be difficult to load a fully loaded magazine on a closed bolt.