According to historian Tonio Andrade, "Scholars today overwhelmingly concur that the gun was invented in China," however multiple independent gunpowder and gun invention theories continue to exist today, advocating for European, Islamic, or Indian origins. Opponents of Chinese invention and transmission criticize the vagueness of Chinese records on specific gunpowder usage in weaponry, the possible lack of gunpowder in incendiary weapons as described by Chinese documents, the weakness of Chinese firearms, the lack of evidence of guns between Europe and China before 1326, and emphasize the appearance of earlier or superior gunpowder weapons. For example, Stephen Morillo, Jeremy Black, and Paul Lococos War in World History argues that "the sources are not entirely clear about Chinese use of gunpowder in guns. There are references to bamboo and iron cannons, or perhaps proto-cannons, but these seem to have been small, unreliable, handheld weapons in this period. The Chinese do seem to have invented guns independently of the Europeans, at least in principle; but, in terms of effective cannon, the edge goes to Europe." Independent invention theories include examples such as the attribution of gunpowder to Berthold Schwarz (Black Berthold), the usage of cannons by Mamluks at the Battle of Ain Jalut in 1260, and descriptions of gunpowder and firearms to various Sanskrit texts. The problem with all theories of non-Chinese invention boils down to lack of evidence and dating. Its not certain who exactly Berthold Schwarz was since there are no contemporary records of him. According to J.R. Partington, Black Berthold is a purely legendary figure invented for the purpose of providing a German origin for gunpowder and cannon. The source for Mamluk usage of cannons in the Battle of Ain Jalut is a text dated to the late 14th century. The dating of the cited Sanskrit texts is often dubious at best, with one example, Sukraniti, containing descriptions of a musket and a cart-drawn gun.
Proponents of Chinese invention and transmission point out the acute dearth of any significant evidence of evolution or experimentation with gunpowder or gunpowder weapons leading up to the gun outside of China. Gunpowder appeared in Europe primed for military usage as an explosive and propellant, bypassing a process which took centuries of Chinese experimentation with gunpowder weaponry to reach, making a nearly instantaneous and seamless transition into firearm warfare, as its name suggests. Furthermore, early European gunpowder recipes shared identical defects with Chinese recipes such as the inclusion of the poisons sal ammoniac and arsenic, which provide no benefit to gunpowder. Bert S. Hall explains this phenomenon in his Weapons and Warfare in Renaissance Europe: Gunpowder, Technology, and Tactics by drawing upon the gunpowder transmission theory, explaining that "gunpowder came [to Europe], not as an ancient mystery, but as a well-developed modern technology, in a manner very much like twentieth-century technology-transfer projects." In a similar vein, Peter Lorge supposes that the Europeans experienced gunpowder "free from preconceived notions of what could be done," in contrast to China, "where a wide range of formulas and a broad variety of weapons demonstrated the full range of possibilities and limitations of the technologies involved." There is also the vestige of Chinese influence on Muslim terminology of key gunpowder related items such as saltpeter, which has been described as either Chinese snow or salt, fireworks which were called Chinese flowers, and rockets which were called Chinese arrows. Moreover, Europeans in particular experienced great difficulty in obtaining saltpeter, a primary ingredient of gunpowder which was relatively scarce in Europe compared to China, and had to be obtained from "distant lands or extracted at high cost from soil rich in dung and urine." Thomas Arnold believes that the similarities between early European cannons and contemporary Chinese models suggests a direct transmission of cannon making knowledge from China rather than a home grown development.