Template:POTD/2019-05-14

Source: Wikipedia, the free encyclopedia.
Rifling
In firearms,
conservation of angular momentum
, improving its aerodynamic stability and accuracy over smoothbore designs.

This picture, taken in 2016, shows the conventional rifling of an Austro-Hungarian 90 mm (3.5 in) M75 cannon, manufactured in 1891, on display at Ljubljana Castle in Slovenia.Photograph credit: Petar Milošević