0.000004 * 320,000,000 = 1,280 deaths for the entire USA.
Your higher estimate yields 10,240 deaths.
In reality we’ve had at least 700,000 deaths.
For those who are infected, the naive Case Fatality Rate is about 1-2%. See for example, https://ourworldindata.org/mortality-risk-covid
There are reasons to suspect the real rate is lower in several countries - many places under test cases, so the denominator in deaths/cases is too small.
Additionally, this rate isn’t static - we were seeing upwards of 10% death rates before effective treatments became known and available.
This whole area might fall into the Sam Clemens quote:
"There are lies, damned lies and statistics"
Since 30 to 40 percent of humans experience no illness with this thing the denominator can be quite different depending on what you use for it. Notwithstanding that...
CFR (Case Fatality Rate) is very different than IFR (Infection fatality Rate). Many many more people have been infected but only the more severe cases tend to end up and be counted in the hospitals.
With this virus, especially the Delta variant, you can pretty much assume at least 80% of the population to get infected if there hadn't been all these measures.
Also not necessarily in the first or second wave...
Although regional numbers vary of course, in my state the death rate by county has averaged between 0.0004 and 0.0032 percent.
Or, in decimal notation, 0.000004-0.000032
These numbers were calculated based on the Covid data repository maintained by the New York Times (https://github.com/nytimes/covid-19-data) and US Census data (http://www.census.gov/).