Bullets do not have rifling, that is done by the barrel of the rifle. Shotgun slugs can be useful well beyond 20 meters. https://en.wikipedia.org/wiki/Shotgun

Bullets do not have rifling, that is done by the barrel of the rifle. Shotgun slugs can be useful well beyond 20 meters. https://en.wikipedia.org/wiki/Shotgun_slug#:~:text=A%20slug%20also%20becomes%20increasingly,(910%20m)%20or%20more https://en.wikipedia.org/wiki/Shotgun_slug#:~:text=A%20slug%.... As a Canadian, I am normally not the one correcting others on the basics of firearms.