While I was sure that I first saw the Armalite AR15 in a Popular Mechanics magazine around 1959 or 1960. I am still sure I did, but I also was such a gun fanatic that when I was 8-10 years old, I asked for gun books and magazines. Here is two pages on Armalite from my 1960 Small Arms of the World. It shows the top "trigger" charging handle prototype. It also lists the weight as 6.0 pounds with a 20 round magazine. probably the slimmer stock and thinner diameter barrel.

My dad was a WW2 vet, who fought on Iwo Jima. He carried an M1icon Carbine, and only said "It never let me down!" (He was in the main compound the night of the big Bonsai charge). I remember as an outgrowth of that, were were having a conversation about rifles, and he talked about the new round they were testing that "was like a 30-30 necked down to 22." I think that was when I got, or shortly after I got the magazine with the prototype article. I think it must have been about 1962, when I was 10, that I got my first "Small Arms of the World" from my uncle. He was the gun guy in the family, and he taught me to shoot.