Topic: Cheonbochong (천보총) and other wall guns
The cheonbochong, which literally means "thousand pace gun", was a type of matchlock wall gun used in Korea in the 18th and 19th centuries. There is a historic record of one firing more than a thousand paces, but many firearms scholars believe it mainly meant a gun that could shoot a long distance. There are a few reputed cheonbochongs in Korea, but it's hard to say if they are truly that type of firearm or not. Some are probably just jang jochong (장조총), or "long matchlock".
A cheonbochong reported back in 1931 by John Boots was 5'5" long and weighed 22 pounds. A similar matchlock is in the Korean Army Museum at the Korea Military Academy, but is slightly shorter; it is about .75 caliber (some wall guns go up to around 1.0 caliber).
My hope is to, someday, have a reproduction matchlock wall gun made and test it out.
I am attaching Boots' book on Korean arms and armor (It has a large section on bows, too!) for your information.