What is a characteristic of full metal jacket ammunition?

Full metal jacket (FMJ) ammunition is characterized by its design, which involves encasing a soft lead core with a harder metal jacket, typically made of copper. This design helps to improve feeding and reliability in semi-automatic firearms. Often referred to as ball ammunition, FMJ rounds are standardized military ammunition that provides consistent performance. This term "ball ammunition" is derived from historical usage and is commonly used to distinguish these rounds from hollow point or other specialty ammunition types.

The other options highlight characteristics that do not align with FMJ ammunition. Soft tips and designs intended for high expansion are characteristics associated with expanding ammunition, which is different from FMJ. Additionally, the assertion that FMJ is only used in revolvers is incorrect, as FMJ can be used in a variety of firearms, including semi-autos and rifles. Thus, the description of FMJ as "ball ammunition" accurately reflects its common usage and characteristics.