It was a beautiful design for its day, as it created the tightest cylinder/frame "seal" for its time. Less gas escaping, at the cylinder gap, kept the most "bang for the Ruble". Muzzle velocity, and accuracy were as good as they were going to get.
Sweden, Norway, Poland, and Greece military and police loved these pistols...
They were also easily "silenced" as the gas seal helped flash and controlled release of propellant. These are of course hard to find and rare...and worth a pretty Ruble...
However, the S&W hand ejectors, came out at the same time, (roughly),...and changed the game with military revolvers.
It came down to the ability to reload quickly. In 1932-33, the Tokarev's came out, and began to phase out the Nagant's.
But it was slow to happen, just like the American 1911, and the S&W .38 Revolver Military Issue, The transition took time to take hold.
Some folks just loved those "wheel guns"...
