A steel-jacketed bullet is a type of ammunition that is commonly used in firearms. It is designed to have a casing made of steel, which surrounds the bullet and helps to keep it stable as it travels through the air. If you are looking for synonyms for a steel-jacketed bullet, you may come across terms like full metal jacketed bullet, jacketed bullet, or simply FMJ bullet. These terms are commonly used to describe the same kind of bullet that has a metal casing or jacket surrounding the bullet. The use of such bullets is regulated in many countries due to their potential lethality and the risks they pose to bystanders and collateral damage.