Soju ranges from 12%-54%. Plus, soju is not well-distilled; it has impurities that vodka does not.

Edited: We’re likely both right. I was in Korea in 1999; back then the alcohol ABV values were quite a bit higher than today. I am also going to guess that the soju ABV content was skewed quite high around the Army bases. For reasons. I also could be wrong. It’s been known to happen.