From Scp Wiki
Item #: SCP-157
Object Class: Euclid
Special Containment Procedures: Item SCP-157 is to be kept in a sealed lead box inside an otherwise empty room. Personnel assigned to study SCP-157 must be unarmed, wearing Class IV biohazard suits. In the event of a suit breach, the compromised personnel will be subject to a cavity search and X-ray. If SCP-157 is not on the offender’s person, they will be subject to a full body MRI before being released.
Description: SCP-157 is a bullet of inconstant make and caliber, shifting form to match the make of any guns brought within 30 meters. Previously, SCP-157 has been recorded changing size as large as an artillery shell. (See Documents) SCP-157 exerts an unconscious pull on persons within 30 meters. Class D personnel exposed to the bullet outside of its lead case report feelings of euphoria and delusions of grandeur. They also report a strong desire to load SCP-157 into a weapon, and become violent when they are restrained from doing so. When a gun is loaded with SCP-157 it will not fire unless pointed at a living target.
Documents: SCP-157’s first recorded use was in April of 1775 during the battle at Old North Bridge in Concord, Massachusetts. SCP-157 was seen again in 1914 on June 28th, where it was used to assassinate the Archduke Franz Ferdinand. SCP-157 showed up a third time in Russia during the October revolution as an artillery shell fired from the Cruiser Aurora. (As the shell fired was a blank, SCP-157 seems to have the capability to change its composition.) The most notable appearance of SCP-157 was when it was a 6.5 x 52 mm round fired from the Italian Carcano rifle that killed John F. Kennedy. SCP-157 was last found in a Titan Missile Silo in 1989, where it was sealed and transported to its current location.
Addendum 157-2: When brought near SCP-042, SCP-157 changed shape to a large bone slug, approximately 3 inches (7.62 cm) in length and 1 inch (2.54 cm) in diameter. The slug was irregularly shaped and appeared to be boiling as if from the inside. At the same time, an orifice in SCP-042 appeared to allow the slug to be inserted.
Testing with class-D personnel have been scheduled to discern the effects of this slug.