The Interface Module is threaded for 5/8x24. The astute among you would have noticed that the 5/8x24 is definitely not a standard threading for 9mm or even .22lr barrels. Typically, though, small-calibers will tend to use finer threading pitched - typically 1/2x28, but 1/2x36 is also very common. Finer threads are both harder to print, and also harder to chase with a tap. What this means for you is that you'll probably need an adapter for your barrel's respective threading.