I experimented with BL-C2 and 223 with varying bullet weights. Seems like 15 years ago. I never achieved the accuracy I wanted no matter what combination of bullet & weight I tried. Rifles I experimented a the time consisted of a automatic, a singleshot, and a match grade bolt action.
Not saying your results may equal mine as things change over the years.
My principle powders for the 223 are H335 & TAC. Varget is good too, but was not around when I did my tests.
Right now with the scarcity of all reloading components commonly used with the 223, I would not hesitate to try different from the norm that includes BLC2.