20 miles/30 km north of Santiago puts you in farm and orchard country. Haven't been there in a long time but rural Chile generally didn't used to be bad - lock your rental car but don't worry too much about walking around town, at least in daytime. Think suburban Yakima, WA in terms of climate and population density.
Any detached house in Chile is likely to have a wall - with broken glass embedded in the top. Guns are hard to come by. I believe semi-automatics and military calibers are prohibited.
Unless you are talking about rifles then you are wrong as far as the semi-autos go.