intended to be aimed and fired by the action of one hand, whether or not it has been redesigned or subsequently altered to be aimed and fired by the action of both hands". The Australian gun laws, which are based on the National Firearms Agreement (1996) and interpreted and enforced independently by each state or territory, considers a "handgun" a firearm that: is reasonably capable of being carried or concealed about the person; or is reasonably capable of being raised and fired by one hand; or does not exceed in length measured parallel to the barrel. History Hand cannons Firearms started in China where gunpowder was first developed. The oldest known bronze barrel handgun is the Heilongjiang hand cannon, in 1288. It is 34 cm (13.4 inches) long without a handle and weighs 3.55 kg (7.83 pounds). The diameter of the powder chamber is 6.6 cm (2.6 inches) while the diameter of the interior at the end of the barrel is 2.5 cm (1.0 inch). The barrel is the lengthiest part of the hand cannon at 6.9 inches long. The hand cannon has a bulbous base at the breech called the yaoshi () or gunpowder chamber, where the explosion, that propels the projectile, occurs. The walls of the powder chamber are noticeably thicker to better withstand the explosive pressure of the gunpowder. The powder chamber also has a touch hole, a small hole for the fuse that ignites the gunpowder. Behind the gunpowder chamber is a socket shaped like a trumpet where the handle of the hand cannon is inserted. The bulbous shape of the base gave the earliest Chinese and Western cannons a vase-like or pear-like appearance, which gradually disappeared when advancements in metallurgical technology made the bulbous base obsolete. In 1432, Joseon dynasty under the reign of Sejong the Great introduced world's first handgun named se-chongtong (세총통). Se-chongtong has a total length of 13.8 cm, inner diameter of 0.9 cm, and outer diameter of 1.4 cm. Se-chongtong is held by cheolheumja (철흠자, iron tong-handle), which allows quick change barrel for the next shot, and fires chase-jeon (차세전, a type of standardized arrow of Joseon) with an maximum fatal range of 200 footsteps (≈250 meters). Initially, Joseon considered the gun as a failed project due to its short effective range, but se-chongtong quickly saw usage after fielding to the frontier provinces starting in June 1437. Se-chongtong was used by