[@Vas Khaleen] 16 inchers? SMALL?

https://youtu.be/uvZS63Osons?t=1m40s

Try a 4 pounder, it's ball is about 4 inch in diameter, and is described as "light enough to be drawn by only two horses."
It's the field gun used by Gustavus Adolphus the great.
A mobile field gun to support the troops.