So far, everyone is pretty much dead on. If you absolutely have to use Unique, stay with about 3.5gr. When you go much above that, you gain velocity too quickly and obviously pressure. Remember, pressure builds very quickly since the HBWC shape, and being seated flush, decreases case capacity very quickly compared to a PB with a crimp groove. At almost anything above target levels (650-750fps) the pressure will begin to deform the base as it leaves the barrel causing accuracy to deteriorate. This can go to the point of splitting the wall of the base or even tearing out a piece causing the danger of a secondary projectile. In either case, accuracy is history. Quicker powders at target speed are best with hollow bases.