Something else to whet your whistle...
M1895 Nagant pistols. By now, everyone in the know has heard about the wondrous "gas sealing cartridge" feature on this gun, or if you haven't, you will, and then you'll hear my other theory.
Ok, the gas seal: It's not a myth, it's very real. The proper M1895 cartridge (aka 7.62x38R or 7.62mm Nagant) isn't made like regular cartridges. The cartridge mouth extends well over the end of the bullet and is crimped down over the nose (must drive pressures up like mad: needs further research). The cylinder on the pistol is designed to move forward when the hammer is cocked, pushing this "cone" of brass cartridge mouth into what is the rough equivalent of the forcing cone. When the hammer falls, the pressure in the cartridge shoves the bullet against the flare on the cartridge mouth and slams it against the forcing cone tightly as it bends out of the way. Viola, gapless revolver.
However, as far as features go this is a relatively useless one, particularly for the Imperial Russian Army. This is my theory.
Nagant pistols needed to be used in all manner of environments, from the borders of the Austrio-Hungarian empire to Siberia to the edge of Mongolia and the Gobi. Heat, cold, damp, dry. You didn't exactly have quick access to the company armorer when you're 1000 miles from Das Kapital on horseback.
So, what to the Russians do? They adopt an extremely robust pistol. The springs on the Nagant are massive, which really helps explain the 30+ pound DA trigger pull. (I hand the pistol to people in the store and ask them to dry fire it, then I end up telling them to keep pulling, i swear it's not broken). The steel is heavy, no thin parts, it's a good solid design.
So why the cylinder thingy? Why bother putting this feature on a gun that's got to live such a hard life?
Lockup. Think about it... What's the bane of the cheap revolver? Poor timing and spitting, or splitting the forcing cone. ruins accuracy too when you've shaved lead off the side of the bullet. Even expensive revolvers fall out of time and start caking the forcing cone over in gooey heavy metal. What does the Nagant do? It shoves the nose of the cartridge directly into the barrel in such a manner that the bullet *can't miss* the forcing cone. It will always, *always* have 100% positive cartridge-barrel alignment or it simply won't fire, because the cylinder will be locked back and the hammer can't be drawn. Even with horribly warn bits and a cylinder that you can use as a baby rattle in the frame, that bullet will always hit the rifling in exactly the same place every time.
Just a thought from your friendly mad scientist.