The most common true instances of this involve Russian ammo, with three particular calibers:
7.62x25 Tokarev: This ammo was essentially a hotter version of .30 Mauser. The case dimensions are almost identical, and .30 Mauser ammo will feed and cycle just fine in a Tokarev. However, the Tokarev ammo would damage or destroy a Mauser C96.
9x18 Makarov: This is effectively a slightly hotter (around 10%) version of .380 (9x17). The bullet diameter is changed from .357 to .362. However, in a pinch, .380 ammo can be fired in a 9x18 gun with no ill effects.
9mm Luger: Russia's new pistols, that they are phasing in to replace the Makarov, fire a very hot-loaded version of the 9mm Luger round. They will function with NATO ammunition, but most pistols chambered for 9mm Luger cannot handle the Russian loading (break out the Ruger P89's, boys).
So Russia did, indeed, create just such a situation on three occasions.