In 1883, the Brazilian government decided to purchase 3,000 new revolvers, and they chose the Mauser Model 1878 “Zigzag” to procure. The officer charged with making the purchase in Europe, however, appears to have done some of his own investigation and unilaterally decided to buy Nagant revolvers instead of Mausers. This naturally caused some scandal back in Brazil, but in hindsight it was clearly the right choice – and Brazil would go back and buy more Nagants in later years.
Specifically, Brazil purchased the Model 1878 Nagant, configured to their specifications. The guns were chambered for 11mm Nagant ammunition, which is actually just another name for .44 Henry Centerfire. Brazil had a significant number of 1866 Winchester rifles chambered for the Henry centerfire cartridge (having purchased them as late as 1891!) and wanted these revolvers to use the same ammunition. The first 3,000 were single action only, but later orders through both Nagant in Belgium and the Suhl consortium in Germany were double action. This particular example was issued to the Brazilian Navy.
Special thanks to Douglas de Souza Aguiar Jr, Curator of the Museu de Polícia Militar do Estado de São Paulo, for his gracious assistance with this video. Collectors and researchers looking for more information on Brazilian firearms should contact the museum through Old Steel Historical Firearms for letters of authentication.