This magazine can be found in western Flor de Oro province, in a Unidad Military Hospital. The accessory case is inside the armoury in the middle of the base.
I approached from the road to the east. There’s a drone jammer here, so it’s very difficult to identify your surroundings, but as usual there are snipers in towers to take out first.
I then used one of the sniper towers near the water as a vantage point to take out some soldiers, but there are very few around. After crossing the road, it’s not far to the armoury and there were no soldiers in my path.
This magazine is for the Dragunov (SVD) sniper rifle only (Villa Verde – CARD) and doubles the magazine capacity from the standard 10 rounds, to 20 rounds.
For sniper rifles with only a 5 round magazine, I definitely recommend the high cap mags, but I’m not so sure 20 rounds is necessary. Nevertheless if you’re trying to collect everything, I hope this helps.