You shouldn't count Mr Halbrook's 2A wankfest as a history book.
The Weimar Republic had banned ownership of new guns. 2 pretty big reasons. The 1st was that it was part of the terms of the treaties after WWI but more importantly, it was an attempt to provide stability in a fragile society because the government was under threat of attack by private armies.
The Nazis were one of these groups.
The law worked. That's why you can find pictures of Nazis and other private militia groups marching around with shovels. They were unable to stage armed coups.
When the Nazis came to power via elections, they greatly expanded gun ownership. They did ban the sale and ownership of new guns to groups like the Jews, Unions, and Communists.
Uh. That's odd. If the Nazis were socialists why would they have Communists on that list. Hmmm.
Anyway.
But anyone else could get a new gun. AND if you joined the Nazi party, you could own any kind of gun you wanted!
But here's the really important part (and the part that the book you showcase forgets to add) registration of guns in Germany was spotty. Very well documented compared to the rest of the world but by today's standards it was nothing to be proud of. That means the Nazis didn't know who owned what guns.
Do you think that any group would have cheerfully handed over weapons to a group actively targeting them?
No.
And look at population. In 1933, the Jewish population of Germany was around 500,000. Germany's census reported a 62is Million population in total. Which means that the jews were less than 1% of the population of Germany.
That number decreased rapidly in the first 6 years of Nazi Germany as 60% of that population fled the country. Reducing the population to what? 200,000?
Those weren't 200,000 trained soldiers armed and ready. They 200,000 people who were isolated from each other. They lacked a central organizing structure and means of communication.
It was only going to end one way.
The truth is that vast majority of Germans owned guns. It's being charitable to say they looked the other way when they likely cheered them on when the Nazis came for the Jews.
The concentration camps were designed by civilian architects and built by local construction companies.