The only Remington Steel barreled gun I have is my FE Trap Gun and its barrels are not marked as to steel type. The only AER-Grade I've recorded in my notes is a 10-gauge, serial number 110,209 that Michael Murphy & Son had a few years back, and the unusual thing about it was that it had the big single barrel lug like often seen on late K-/KE-Grades, like the front barrels in this picture.