Dug these three 40 rd mags out last nite.I always used them with no problems in a Palmetto car 15 I've owned since 1978.The floor plates are unmarked,2 are identical,one on left is a bit different.All 3 are steel,not aluminum... Anyone know for sure if these were AR15 40s or AR180?? Or ??????? Who may have made them??? Please let me know what you think.TIA.

They are AR 40's and were made in teh early eighties. I bought several for my M16A1. They used to sell for around $18 - $20 each. I still have some in a closet somewhere.They really worked very well with no jams or failure to feeds.
They look very similar to some PMI's I used to have.