|Drawing of a Hu Dun Pao, from 'Lian Bing Za Ji (《練兵雜紀》)'.|
A typical Hu Dun Pao has a length of one chi nine cun, and weights thirty-six catties. It has bore diameter of two cun, usually loaded with six to eight liang of powder, fifty large lead or iron shots or one hundred smaller ones, and a large stone ball (later replaced by iron ball). For its size, Hu Dun Pao is an extremely powerful cannon, yet it is light enough to be carried by one or two men. Hu Dun Pao has a characteristic bipod that enables it to be staked firmly to the ground, so that the cannon will not jump violently due to recoil. The bipod, combined with the compact size of the cannon, allows multiple Hu Dun Pao to be fired in close proximity to each other, potentially increase the firepower manyfold.
|A very large Hu Dun Pao at Wolongtai Great Wall section, Xinyang, Henan, China.|
|Korean copy of the Hu Dun Pao, known as Hojunpo (호준포). Korean copies of Chinese cannon tend to be much smaller than their Chinese equivalents.|
Although a very successful design, the limitation of Ming Dynasty firearm technology was clearly evident on the Hu Dun Pao. The Chinese never developed grapeshot and canister shot, thus powder, sabot and shots have to be loaded separately into the barrel, greatly reducing rate of fire as well as range and firepower (due to larger windage). Besides, Chinese did not develop wheeled gun carriage on their own until very late (they adopted gun carriage from the Europeans, and later devised several indigenous designs for their newer cannons, but its use was very uncommon), which severely affected the size, mobility and battlefield maneuverity of their artillery. Chinese cannon had to be made very light to be transportable at all, yet the advantage of lighter weight could not be fully utilised because it had to be staked to the ground.