I am asking this question as a spin off to a thread about China's military weakness in the 19th and early 20th Century. Here in America, there was King Philip's War, between English settlers and Natives, breaking out in 1675. King Philip (Metacomet) commanded Native American warriors from a society that to some degree was producing, or at least repairing, guns. In order to counter him, the capture of the Native forges was a part of the English settler strategy.
Among more urbanized cultures, the Turks & Japanese made their own, and somewhere I have heard that firearms manufacture of "Khyber Pass copies" in the region of Pakistan goes back to the 19th Century.
Well, China would certainly fit the bill as firearms originated from the east, and many countries adopted and produced cannons and guns as they came into contact with it, but perhaps the most interesting country when it comes to firearm development is Korea of the 15th~16th century. Known back then as Joseon.
Korea developed various types of hand cannons, designed to shoot bolts instead of bullets- although they quickly became obsolete once they were introduced to guns. Their most famous weapon is likely the Hwacha, also doubly serving as a medieval rocket launcher.
Their development in cannons were also a large contributor to their victory in the Imjin War (aka the Japanese invasion of Korea, 1592~1598), their Panokseon carried up to 24 cannons and their broadsides being greatly effective against the smaller, boarding-focused Japanese ships. Their probably coolest artillery though were probably their cannons that shot medieval grenades, which would burst into a mass of shrapnel, also developed in the late 16th century.