155 scenars bullets minimum velocity is 2900+ fps. (recommend varget)
or 175 SMK minimum veloctiy of 2600 fps. You won't have any problem reaching out to 1K with either of that.
Also, accuracy at 1000yd will be problematic with your 168gr SMK, as it will probably go sub-sonic before getting to 1K. Stick with the 155 scenars pushed at higher velocity or the 175 SMK.