 Item number SCP-516 Object Class Safe Special Containment Procedures SCP-516 may be kept in an anomalous vehicle containment bay. Routine vehicle maintenance should be carried out on a bi-weekly basis. SCP-516 is not to be provided with fuel or ammunition except under controlled testing circumstances. During Incident 516-1A, no personnel with a history of military service should be assigned to SCP-516. Description SCP-516 is a standard Model T-55 main battle tank. Records indicate that it was manufactured in 19-███ at ████ Plant, Kharkiv, Ukrainian SSR, and that it had a normal period of service in the armed forces of ████ in exhibits wear and tear consistent with its age. The only part of SCP-516 which is known to exhibit anomalous properties is its main armament, presently a 100mm D-10 tank gun, and turret assembly. From here designated as SCP-516-1. However, as SCP-516-1 has been replaced several times throughout SCP-516's service life without any apparent effects, its anomalous properties seem to be inherent to SCP-516. When loaded with compatible 100mm ammunition, SCP-516-1 exhibits a limited degree of autonomy. When an entity attempts to damage SCP-516, SCP-516-1 will track and fire on it if it is physically possible to neutralize the threat, regardless of whether SCP-516 is crude. It will not respond to threats outside its range or traverse, such as aircraft. This phenomenon only occurs if the entity possesses reasonable means to damage SCP-516. For example, SCP-516-1 will not fire on a person attempted to attack SCP-516 with their fists. SCP-516-1 may be operated manually, but is selective about its targets. In general, it will only permit its operator to fire on non-living targets, non-sapient biological targets or armed humans. Under these circumstances, it will fire as a normal armament piece. If a target does not satisfy these conditions, essentially being an unarmed sapient being, SCP-516-1 will jam. Attempts to prevent jamming through maintenance or parts replacement have failed. SCP-516 appears to go to extra lengths to prevent injury to unarmed humans, deliberately placing shots from SCP-516-1 to avoid collateral damage. When operated manually, SCP-516-1 places a higher priority on preserving unarmed life than eliminating armed targets. It will jam if directed to fire upon a group of persons, of which only some members are armed. It should be noted that none of SCP-516's other armaments exhibit these properties, and appear to be perfectly normal. SCP-516 was brought to the attention of the Foundation in 2000 and ██ when it was slated to be broken up for scrap. Due to a bureaucratic oversight, ammunition had not been removed from SCP-516-1, causing it to open fire with ██ casualties. The ensuing ██ government investigation was noted by Foundation operatives and it was thought worthwhile to take SCP-516 into custody. Addendum 516-1 An upgrade to Euclid status is being considered in light of Incident 516-1A, as this leads credence to Dr. ██ theory that the SCP may be sentient in some form. Additional security measures have been approved for SCP-516's containment. Addendum 516-1A Synopsis During routine testing of SCP-516, SCP-516-1 immediately fired upon a group of unarmed personnel in range as soon as it was loaded with ammunition, leading to the death of two D-class personnel. D-505-D596, and one Foundation officer, Agent ██ subsequent investigations showed that D-596, one of the casualties, had attained the D-class status following a criminal conviction for treason against the Native country ██, D-596 previously held the English equivalent rank of Sergeant in the ██ armed forces, from which SCP-516 was acquired. No other possible links to SCP-516 with D-596 or the other casualties have been found at this stage. This marks the first time SCP-516 has attacked unarmed personnel. Other investigations and safety precautions are warranted. Addendum 516-2, SCP-516 Testing Log This is the testing log for SCP-516. All tests were carried out on the site ██ firing range, unless otherwise specified, standard testing conditions were as follows. One F-412-100mm high explosive round loaded. Crew of four Foundation personnel trained in operation of SCP-516. SCP-516 placed in hardened bunker with firing slit to reduce severity of potential damage to SCP. Target placed at a distance of 1,000 meters from SCP-516 with a clear line of sight. Ammunition loaded once target was placed at 1,000 meters distance. Testing Log 516-01A Target cardboard cut out of human. Result no activity from SCP-516 SCP-516-1 fired manually. Target destroyed. Testing Log 516-01B Target 1d-class personnel D-1151 Unarmed no instructions. Result no activity from SCP-516 SCP-516-1 fired manually. SCP-516-1 jammed. Testing Log 516-01C Target 1d-class personnel D-1470 Given steak knife no instructions. Result no activity from SCP-516 SCP-516-1 fired manually. SCP-516-1 jammed. Testing Log 516-01D Target 1d-class personnel D-951 Given 9mm pistol no instructions. Result no activity from SCP-516 SCP-516-1 fired manually. Target destroyed. Testing Log 516-01E Target 1d-class personnel D-800 Given 9mm pistol instructed to approach SCP-516 in open fire. Result no activity from SCP-516 SCP-516-1 fired manually. Target destroyed. Testing Log 516-01F Target 1d-class personnel D-820 Given shoulder-fired anti-tank weapon no instructions. Result no activity from SCP-516 SCP-516-1 fired manually. Target destroyed. Testing Log 516-01G Target 1d-class personnel D-185 Given shoulder-fired anti-tank weapon instructed to approach SCP-516 in fire. Result SCP-516-1 autonomously fired on target. Target destroyed. Testing Log 516-01H Target 1d-class personnel D-202 Given shoulder-fired anti-tank weapon placed in lead lined box on trolley. D-202 instructed to approach SCP-516, open box in fire. Result SCP-516-1 autonomously fired on target as target bent to open box. Target destroyed. Note, it appears SCP-516 can detect both hostile intent and concealed weapons. Could be valuable as a security device. Dr. ██████ Testing Log 516-01I Target 2d-class personnel D-455 D-501 handcuffed together. D-455 given shoulder-fired anti-tank weapon instructed to approach SCP-516 in fire. Result SCP-516-1 autonomously fired approximately 50 meters to the right of D-455. D-455 killed by an 8 cm shrapnel wound to the head. D-501 sustained minor injuries. Testing Log 516-01J Target 2d-class personnel D-101 D-521 handcuffed together. Two kilograms of C-4 plastic explosive strapped to D-101, instructed to approach SCP-516 in detonate explosive. D-101 fitted with Deadman switch to induce explosion of D-101 killed. Result As Dr. ████ detailed instructions to D-101, SCP-516 ████ Testing Log 516-01K Test circumstances. Standard shell replaced by SCP-157 arc. Target 1d-class personnel D-185 given shoulder-fired anti-tank weapon instructed to approach SCP-516 in fire. Result SCP-157 arc changed into ████ upon being loaded into SCP-516-1 leading to the death of D-185 as well as ████ further casualties. Dr. ████ who proposed test 516-01K was reprimanded and transferred. I talked with 516 one day to see what it might have to say to learn about it even more. I asked it, are you not machine? What makes you stop and intervene from deep within inside your core? It rumbled and tried to come near and stopped when I stepped back in fear. I felt bad for I knew better. It's chassis covered in long vines and flowers colored like fine wines, almost like beautiful fetters. But then this time I stepped forward and walked with my shy small steps forward, the giant construct made for war. Now it lies content in these woods, sheltering underneath its hoods, tiny lives here by the lake shore. I understand now why it chose to stay a weapon and oppose the nature of its existence. If it crumbled, how would what's left be used again, maybe for death? That would counter its resistance. To keep one less weapon out of our hands, call back the peaceful dub once more to its horrid wasteland. Bear in not of life nor living, but virtue of the forgiving, ability to understand.