If you are going to reload, I have been told the Lee die set is for resizing 32-20 brass & doesn't work well to reload the original 7.62x38r cases. Apparently RCBS makes a set designed to work with the original brass, but they are about $160. The Nagant revolver is a "gas seal" design where the case mouth is pressed into the barrel upon firing. This seals the powder gases in the barrel & adds around 150 fps. Using 32 S&W ammo, the gas seal feature doesn't work, & you get a much louder report & gases/debris blasting out around the cylinder. Anyone shooting this ammo in a Nagant revolver should wear a heavy glove on their shooting hand & eye protection! I found this website while looking for info on reloading for the Nagant revolver.
http://www.h6x.net/reloading_7.62_nagant.htm