I've actually seen blow-back weapons fired with black powder, including a Sten gun. They become unusable normally before the first magazine is expended due to powder fouling.
A weapon that has to be broken down and cleaned every 15 shots so that it will continue to function isn't particularly useful, and can be very, very deadly to its owner in certain situations.
When Winchester and Remington started developing semi-automatic .22 and .25 caliber rifles in the late 1800s, they purposfully made them so that standard .22 and .25 ammunition couldn't be chambered because most of it at that time was still loaded with black powder.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.