Kobra,
Compare the low max loads in the Hornady loading manual to the maximum on the websites for those powder makers.
http://data.hodgdon.com/main_menu.asp (for Varget and BL-C2, loaded at 2.800 COAL)
Varget max is 45.0gr and BL-C2 max is 46.0gr (for both 175 and 180gr bullets)
Alliant Powder - Reloader's Guide (RL-15 loaded at 2.800 COAL)
RL-15 max is 45.0gr (for 180gr bullet)
For Varget and RL-15 there is an accuracy node at 45.0gr and most people use the accuracy node at 43.5/43.6gr. If you want a modest load there is also an accuracy node at 42.2gr. I found with the 178gr AMAX bullets that I needed to have a jump of .015 to .020 to maximize accuracy (jump from ogive to lands).