how do you shoot starvation, no fuel, nano, bio, weather, drought, and drone/satellite based emp weapons? Is it the round count that matters?
They already know what everyone has, thanks to smart devices, alexa/siri, personal assistantss, geolocation, etc.
Shutting off accounts, web access, and ability to buy and sell will be what the 'door knocking' will manifest as. Not to mention rewards for snitches which will be family, neighbors, and coworkers. Be logical.