 In a study of Zululand District Municipality, South Africa, it was found that most improvised firearms were crude, 12-gauge shotguns, with a simple pull and release firing mechanism; like the .22 rimfire cartridges shotgun shells also operate at low pressures, making them more suited for use in weak, improvised barrels.Even in the absence of ammunition, homemade powder can be used; such firearms were the subject of a crackdown in the People's Republic of China in 2008.Danao City, in the Cebu province of the Philippines, has been making improvised firearms so long that the makers have become legitimate, and are manufacturing firearms for sale.