I'm considering an SCP-186 [meme?] / Carveloa Incident [flash-game] / Siberian Expedition [obscure RL history] RP.

In short, an RP set in 1917 using surprisingly advanced weapons for its time like the RSC Mle-1917 semi-automatic, bolt-action rifles chambered in the ungodly-huge 9.4x64mm Brennke and other sillies.