What characteristic do tubular magazines use for bullets?

Tubular magazines are designed to hold ammunition in a way that allows for reliable feeding into the chamber of a firearm. The characteristic shape of bullets used in these magazines is a rounded or blunt head. This design is crucial because it helps to prevent the rounds from snagging on one another during feeding, which could lead to jams or feeding issues. The rounded shape allows for smoother passages as the bullets feed into the chamber, especially as they move through the magazine in a stacked formation.

In contrast, other bullet shapes, such as flat or pointed heads, could create problems when loaded in a tubular magazine because they can catch on each other or the magazine's interior as they shift and move during cycling. This could lead to malfunctions, making the rounded or blunt design the most suitable choice for ensuring the consistent and reliable feeding of ammunition in tubular configurations.