I tried using IER scopes on a BLR, and ended up removing them. The LER may be a bit much, but will work decently to 100 ~ 150 yards if you can get sight picture. The problem I had was parallax, even with a 3-12 Burris. At 200 yards, I would get consistent 4-5" vertical point of impact shifts; I had no such problems at 100, and the scopes worked quite well. The problem may well have been my eyesight rather than the scopes, but I ultimately had no faith in the sight picture past 125-150 yards.