Come on in, warrior! Still breathing aye? Good to hear. Here's a task for you. There's this customer, showed up outta nowhere with an urgent order and the bitch wants specific equipment, the one our glorious mother Russia produced, and my heart aches that the good of the state has to be sold to whoever. Judging by the accent, the fucker is from abroad. But the cash is noble and the connections he provides are no joke. Anyway, you need one military battery, the heavy one, and several OFZ shells. I feel you'll have to sneak on the military base for it... The place is inhospitable, I know, but you won't regret it when the checkout time comes. Plus, I’ll provide you with a special gift for this. Will you take the risk?
The items required for this quest need to be found in raid. The only map with them is Reserve, but there is a small chance for a scav to have it in their backpack. The 6-STEN-140-M military battery is a large 4x2 slot item that resembles a black/brown box. It can most commonly be found sitting on or near tanks. The OFZ 30x160mm shells can be found throughout the Reserve on tables, shelving and at the rear side of every tank on the map, on the ground. Both of the items required for this quest can also be obtained from the Scav Case in the Hideout.
A reliably good source for OFZ Shells is the RB-BK marked key room. A reliably good source for the Tank Battery are the RB-ST and the RB-GN rooms.