If you want to shoot 55s then H380, 4895, or 4064 have all worked well for me. My favorite 55 load is 36.0 grains of imr 4895 and a 55 nosler BT or hornady sp.
The 10 twist will let you go heavier as well. I like the 65 sierra gameking and the 63 sierra smp (the latter will stabilize in slower twists as well) with varget 4895 or 4064.
For varmits and predators the 55's are probably the best way to go unless you really want to stretch the range out. In that case a heavier target bullet will help you with wind drift.
Good luck
