The suppressor is described as:
Reduces the sound of gunfire at the cost of stopping power.
You can find this in southern Flor de Oro province, at a Unidad airfield, swarming with soldiers. A “Gasoline Air Transport” side mission is nearby. The weapons case is located near some parked vehicles, behind a fence.
I tried to get this accessory by stealth, but I don’t think it’s possible during the day. Maybe at night. But I ended up just shooting all the Unidad and calling in some rebel support. Grenades and the M203 grenade launcher were very useful for this!
Not many LMGs accept this suppressor (in fact, only one, the Stoner A1 LMG), so it’s a bit of a niche accessory – however – if you want to get the Stoner and give this a go, it’s fantastic! It’s like having some kind of god gun that takes out enemies wearing body armour and vehicles with ease, and you can still get stealthy kills with it!
Even if you rarely use an LMG, get the Stoner and get this – have a go. It’s fun as hell!