A quarrel or bolt is the term for the ammunition used in a crossbow. The name "quarrel" is derived from the French carré, "square", referring to the fact that they typically have square heads. They are typically shorter than traditional arrows and, though some may be longer, can be fired repetitively in some cases.

Bolts and arrows have different flight characteristics. Bolts fall at the same rate, independent of the speed of flight. Arrows, in contrast, depend on gaining lift in flight, and hence have their centre of balance at a point about 9% of their length forward of their center. This is called "point planing".

References

• Stone, George Cameron (1999). A Glossary of the Construction, Decoration, and Use of Arms and Armor in All Countries and in All Times. Mineola NY: Dover Publications.