A short balkan musket

[David R]

Lots of reasons for flint and even matchlocks to continue in use. Ease of supply is one reason certainly, but problems with storage is another. Matchlocks continued in use in South America til quite recently because the humidity corroded cartridges into uselessness.
Political reasons also apply. Most Imperial governments preferred the locals to be denied modern weapons. A current example I have heard of is that native Tibetans are allowed Matchlocks but not modern guns by the Chinese government Matchlocks are adequate for hunting but are not considered a threat to the local government forces.

[Philip]

Here is an example of a matchlock dated 1844 with a Spanish inscription on the lockplate, from a remote area in one of the Spain's former colonies in the Americas. What is notable, besides the long-obsolete mechanical design, is the shape of the buttstock, characteristic of parts of southern Europe two centuries or more earlier, totally unaffected by subsequent stylistic developments. The barrel of iron with flaring brass muzzle, cal. .62 in., overall length 41.5 in.

(Royal Scottish Museum, Edinburgh, inv. no. 1894.133)

[Philip]

Originally Posted by David R

A current example I have heard of is that native Tibetans are allowed Matchlocks but not modern guns by the Chinese government Matchlocks are adequate for hunting but are not considered a threat to the local government forces.

That might have been true a half-century ago, but in more recent media images I have noted show Tibetan nomads allowed to keep arms for hunting carrying bolt-action Mosin-Nagant M1891s and Mauser Mod. 1898s from the pre-World War II era, with native-made bipod barrel legs added to the forestocks in traditional fashion. The rifles are chambered for calibers formerly used by Nationalist and Communist forces in China for much of the last century so ammunition supply must not have been a problem, indeed it is possible that they were supplied by the authorities since besides hunting, there isn't much of a livelihood for these people besides herding yaks and other animals.