I have a pre ban XM15A1 RIA rifle that shoots and functions good, with triangle grips, iron sights, 20'' barrel, and old style butt stock with cleaning kit compartment, I cannot find any info on Rock Island Armory AR's, all I know I they were made in the mid 80's beyond that I know nothing. Anyone that has any info on these I would greatly appreciate it if you would enlighten me about it. Thanks