Fun fact for you. Modern firearms haven't used black powder for a very long time, that's why when people fire rifles you don't see huge clouds of smoke
There are also many kinds of gunpowder, rifles use different powders to say shotguns or pistols. Although often times shotgun and pistol ammunition uses the same class of powder (slower burn rate iirc)
You'd need to look at the actual implementation, it's hard to speculate from a tiny amount of data. What game are you referencing?
And as someone who has done multi threaded programming I can tell you that for games it is unlikely that they can just add more cores. You need work that truly can be split up, meaning that each core doesn't needs work to do that doesn't rely on the results from another core
Graphics rendering is easy for this and it's why gpus have a crazy number of cores. But you aren't going to do graphics compute on the cpu