I had a hart barreled,Hs per stock rifle made by a local gun smith. It has a 1 in 9 1/4 twist. it shoots the smk 130 very well @ 100 yds. Best group around 1/4 inch. But the 200 yd accuracy is just around 3/4. I have tried the 168 smk that will shoot 5/8 inch. I use imr 4831 powder,51 gr with the 130,and 52 gr with the 168. the 200 yd accuracy is more important to me anyone have an idea on smaller groups at 200 yds