Using a Wire Tool on a SAM site will reveal a Power In port and Has Target, Low Ammo, and No Ammo. Quite recently, a Defender mode was implemented so that SAM sites will only shoot at MLRS rocket barrage strikes. It takes roughly 3 SAM sites fully functioning and facing the direction of the Abandoned Military Base to shoot down a full barrage of 12 MLRS rockets.
When not in defender mode, SAMs indiscriminately fire at any flying player-piloted vehicle, even with or above their vertical plane. Placing them in a non-confined space is key, as impacts with objects around them will cause ammo waste and damage to the SAM site and the structure around it. Their range depends on the height of the vehicle passing, but usually, being within a square of the SAM site is deadly.
Historically, SAM sites were one of the fastest ways of getting your base raided. With the implementation of minicopters and scrap transport helicopters, large clans commonly use these modes to transport members. When shot down by unmarked bases possessing SAM sites, they are bound to get rattled and retaliate.
For those wishing to destroy (for whatever reason) a SAM, they are highly susceptible to fire-based attacks. SAM sites can only be acquired through spending 500 Scrap at Outpost. They may be picked up once placed.
Be sure to check out our SAM Site Beacon guide for more information!