The US is by no means unique as a country which has armed its citizenry in order to overthrow an oppressor. It happens often in third world countries to this day. And to suggest that it was because of a US gun culture that tyrants were overthrown is quite a claim. I assume part of your claim refers to Adolf Hitler. If this is the case, the influence of gun culture could hardly be accepted as a cause for Hitler's defeat except in perhaps the most minutely debatable way - the noteworthy reasons for his defeat wouldn't even entertain your suggestion.
SSC, I'm not sure what you mean. It's the culture of the then US citizenry that led to it engaging 20th Century tyrants as it did. Prevalence of gun ownership was only a piece of the overall construction of that culture. Whether that citizenry's culture would have developed as it did to perform as it did in the 20th Century without its precursors holding very personal views about gun ownership I don't know. The argument is not mine, but when you think about events of the 20th Century and the role played by US citizens in defeating genocidal governmental tyrannies one has to wonder whether the US gun-owning culture played a role in US citizens' willingness to do what they did to prevent an even worse world than we have now.