Today I was sighting in a new scope on this rifle. I has some American Eagle 223 50 grain hp rounds that were given to me. So I figured to zero with these rounds. By the time I was through, I was putting some 50 grain sierras loaded with benchmark in a 1/4 in circle at 100 yards. This thing is a bug zapper with the 50 grain bullets. I have shot several 65 to 68 grain through it without much luck. I will try the 53 Amax, 55 Amax and the 60 Amax in it next. I was beginning to wopnder if this rifle would ever group less that 1 1/2 inches with anything.