I was reading today about the AK47 assault rifle. It seems this has been adopted in such huge numbers largely because of its insensitivity to dirt.
Today’s invention is therefore a technique by which more accurate, and therefore less grime-tolerant, weapons can clean themselves.
The rounds used would include an occasional one with no bullet. Instead, the cartridge would fire a plug of wadding, soaked in cleaning agent, down the barrel, clearing out the detritus left by previous rounds and helping to keep the rifling suitably polished.