While this is technically possible, it is not that easy. In other words, someone who is technical and experienced enough to manually create a lower like that is very likely to have extensive experience with firearms anyway (and likely owns many).
You'd be surprised how motivated someone in a gang could get watching a ton of videos on youtube just to get access to a gun police cannot "trace" in a meaningful way.
You'd be surprised how motivated someone in a gang could get watching a ton of videos on youtube just to get access to a gun police cannot "trace" in a meaningful way.