My 18" really likes two loads but both for 178 AMAX. The 175's and 178's will do everything the 168's can do, but better. Especially at 600+ yards.
43.8 Varget 2.815 COAL CCI BR primers Black Hills Brass = 2488 fps with 7SD and shoots .5 moa all day long.
43.6 4064 same as above = 2566 with 9SD and same accuracy.
Both loads have no pressure signs and primer pockets still tight. I have almost an unlimited supply of brass so have not had the need to run much through the small base die. I haven't seen any real difference on the pieces which I have sent through it.