The TA31H is described as:
An ACOG 4x scope with a horseshoe reticle.
It can be found in south-west Espiritu Santo province, at what looks like a hilltop cartel barbecue or something. There are six narcos here with good views down the hill. The accessory case is sitting on a table.
I approached this from Espiritu Santo Charlie rally point, to the west and went the 260m up the hill on foot. You do need to be careful not to be seen on your final approach, but I employed the flare gun as a distraction to draw the numb skulls down one side of the hill and away from the case, then took them out from behind. Worked a treat!
As stated, it offers a 4.0x zoom. It says this is compatible with ARs and sniper rifles, but it’s the standard scope you start with for sniper rifles until you pick up something else.
You have to collect this in order to use it for assault rifles, and although I hate this as a sniper scope, it’s my favourite AR scope because it’s clear, with good markings and doesn’t obstruct much of your view – and it zooms in well for medium range engagements, which is how I use an AR.