Make no mistake about it, pistol squats are a full-on legitimate leg strengthening exercise in their own right. The only thing standing in the way is learning how to be rock-solid through the full range of motion. To accomplish this level of stability, I highly recommend using your glutes. No, not the big muscles you sit in a chair with. I’m talking about your other glutes, the ones few people know even exist let alone focus on contracting in their leg work.
Check out this video to learn about these “other glutes” and how you can use them to improve your squats and leg strength.