From an earlier answer on this topic

it was actually Weimar Germany that instituted wide-scale legislation restricting firearms in 1922 with the Republikschutzgesetz (law for the protection of the Republic). Under the rubric of "endangering public safety," the Republikschutzgesetz outlawed the organizations from owning unauthorized weapons, the creation and brandishing of a weapons arsenal, and criminalized the failure to report on the existence of weapons arsenal. But gun control and regulation was not the primary focus of the Republikschutzgesetz but rather to restrict the operations of various anti-republican groups and provide grounds for their prosecution. The Republikschutzgesetz's provisions on firearms were predicated upon a pre-existing January 1919 Reichstag legislation which banned the private ownership of firearms to meet provisions of the Versailles Treaty which called for a wide-ranging German disarmament, including non-state affiliated militias.

The 1928 Law on Firearms and Ammunition liberalized restrictions on guns and their ownership, but still provided a strict regimen of regulation and permits. Applicants for gun ownership had to demonstrate both necessity and reliability. In the latter case, members of itinerant groups such as gypsies or criminals were forbidden from gun ownership. The 1928 law also waived the need for a permit by state officials since they had already demonstrated the requisite amount of political loyalty and responsibility.

The Third Reich's 1938 Reichswaffengesetz had much of the same language as its Weimar predecessor, but it paradoxically was a simultaneous liberalization and restriction of existing gun laws. The Reichswaffengesetz ended a number of restrictions in the 1928 law for rifles and shotguns and largely focused on restricting private handgun ownership. It also eliminated the need for transfer permits for rifles and shotguns and held that a legal hunting license sufficed as a permit for holding firearms. members of the NSDAP were also a privileged group and thus could more easily obtain the requisite permits.

Where the Reichswaffengesetz and its Weimar equivalent parted ways was the former's restrictions on gun ownership by individuals deemed subversive to the state. To an extent, this was a change in degree as the Third Reich was much more explicit about who was a state enemy while the Weimar law was more circumspect. The Reichswaffengesetz provided a later justification in November 1938 for the Interior Ministry to prohibit Jews from owning any type of dangerous weapon. The Reichswaffengesetz was of a piece with other legislation of the Third Reich: it set up Aryan Germans as a privileged elite, especially those who served the state and the party, while restricting the civil rights of those excluded from this racial compact.

As for Ben Carson's recent comments and the wider sentiments about gun legislation in Germany as exemplified by all too typical facebook posts and this bumper sticker, they have a number of faults that makes their historical analysis very problematic. First off, these type of arguments tend to come up quite short when it comes to both explaining the context and the nature of these laws. For example, the Weimar government passed these laws on gun ownership in no small measure because there were a large number of paramilitary Freikorps groups operating in Germany who explicitly stated their goal was to overthrow the Republic. Sometimes these stated goals turned into action as with the Kapp Putsch or the NDDAP's Beer Hall Putsch. Furthermore, examining the Reichswaffengesetz in isolation from other German legislation loses a good deal of the picture; arguments as exemplified by Carson's assume that gun legislation preceded wider erosion of civil liberties when that clearly was not the case here. The Nuremberg Laws, which provided a whole panoply of civil rights restrictions, preceded the Reichswaffengesetz by a good three years. From a historian's standpoint, it is more valuable and fruitful to look on laws on gun ownership as part of a larger process of social exclusions and restrictions directed at Jews rather than a vital precondition for them.

Finally, another big problem with this type of analysis is it blithely assumes that American gun culture and patterns of ownership are a universal given. Not only does this portray American gun culture as a monolithic (which it clearly is not- Americans own guns for many different reasons beyond hunting and self-defense), but relies upon the unspoken assumption that different cultures and societies view guns the same way and possessing the same function. This is a highly erroneous way to view the issue as patterns and attitudes to gun ownership are often contingent on a myriad number of factors ranging from recent history, legal traditions, social norms, or economic development. While there might be some overlap with US gun culture, there are also differences as there would be with any material item (cars, computers, home ownership, etc.). To homogenize history in this way is lazy and unreflective at best, and needlessly politicizes an important topic of analysis.

Sources

Evans, Richard J. The Coming of the Third Reich. New York: Penguin, 2005.

Harcourt, Bernard E. "On Gun Registration, the NRA, Adolf Hitler, and Nazi Gun Laws: Exploding the Gun Culture Wars (A Call to Historians)." Fordham Law Review 73 (2004): 653-80.