Effective range? I'd say likely in the the 700 yard range for reliable bullet expansion. I killed my giraffe at 286 yards with a 250 grain GMX and I killed a black wildebeest at 318 yards with the same bullet. With the proper optics I'm sure it would be a reliable 500-600 yard rifle but I don't think I'd want to do a lot of prone shooting with it. My limit on sticks is around 300 yards.