The lawyers that write for the Volokh blog do a good job as usual. Lots of info on the history of why suppressors were regulated, and it wasn't about crime:
https://www.washingtonpost.com/news...ion-act-and-silencers/?utm_term=.d3e9cfed739d
https://www.washingtonpost.com/news...ion-act-and-silencers/?utm_term=.d3e9cfed739d