I have found that the 175 smk is not very sensitive to seating depth. My best loads are loaded to 2.800" and 41.7 grs of IMR-4064 in lapua brass and 42.2 grs in Win brass all CCI BR2 primers. This is the military duplicate load that I have shot numerous times to 1000 yards with no issue. Velocity is around 2550 in a 26" 12 twist barrel. Also 43.5 of varget shot about the same for me....
This bullet is by far the easiest bullet I have got to shoot. I will also add that these loads are jumping .160! (longggg throat Remington chamber). So main thing keep seating depth consistent until you get you powder charge close then fine tune with seating depth, then fine tune powder, then tweak seating depth, then again and again it seems like!! Just stop when you are satisfied with the accuracy. You can shoot the barrel out of a gun just chasing that magic load!
This bullet is by far the easiest bullet I have got to shoot. I will also add that these loads are jumping .160! (longggg throat Remington chamber). So main thing keep seating depth consistent until you get you powder charge close then fine tune with seating depth, then fine tune powder, then tweak seating depth, then again and again it seems like!! Just stop when you are satisfied with the accuracy. You can shoot the barrel out of a gun just chasing that magic load!