Weird and wonderful. The cylinder moves forward when cocked, sealing the end against the barrel, supposedly to prevent the escape of gasses and make the round more potent. As Jiro stated, this enabled it to be silenced, as there is no gap.
The ammo is recessed below the neck of the brass, I guess also for sealing purposes. For when this thing was invented, it was over-engineered.
As Scott said, ammo can be found online, but hang up finding it at your smaller shops or Wally World.
Actually, quite a fun plinker, and a solid gun. A little stiff, remarkable for the age of the gun.
I have a 1937 Tula, and it's a great plinker. It isn't super accurate, but no problem punching out a paper plate at 25 yards. The trigger pull is extremely heavy though, probably because of the gas seal system I would guess. The ammo is available, but it is not cheap. You can get a conversion cylinder to shoot cheaper and more plentiful .32 ACP, but then the gas seal does not work, and you use some velocity.
this is a gun for a reloader.32/20 empties will work.and you have to find a charge that is safe.bullseye or 700X will work.and use lead bullets.
They sell for $79.I am not sure the replacement cylinder will drop in.
I have one, and my shooting buddy has four. He does my reloading, as I haven't been able to get the dies yet. Once I do, I will be using his load data.
Accuracy is okay, power is light - great plinker with soda cans or steel spinner targets.