1. Fold the stock (click middle mouse on weapon)
2. Upload magazine (not all weapon)
3. Remove the handle
4. Don't forget to remove bullet in the chamber

before
after

Use Rigs for space economy. Recommend storing all small loot (bullets, medicine, etc.) in rigs.
Divide Rigs by item types.
Use button "Configure Items" for quick equipment required items from rigs.

All big loot (armor, weapon) you can storage in backpacks

For longterm storage (money, red 2x1 and 2x2) you can use combination of backpacks and rigs.
You can place into one backpack 2 backpacks and 2 rigs:
optimal choise (20 cells in inventory = 50 cells)
Cowhide -> Cowhide -> RUSH -> [FA Commander + FA Commander]


!!! Don`t recomended use this method for all items and all inventory, it`s very impractical.

For popular sights (1x/4x, 3x, 1x/6x, 2x/7x) you can save 1 cell if you place it on Dedicated BM 59 Top Rail or Uzi Top Rail (1x/6x, 2x/7x need place in 30mm Rail Sight Mount before)
before
need to buy
after

!!! The only drawback is that the sights will not be available when assembled weapon at a gunsmith's.

This method works only if you don`t have empty space in storage + only for non-operation supplies.
You can temporarily fill out storage by opening empty backpacks.

1. Put loot in equipped backpack (or chest rig)
2. RMB (right mouse button) on backpack - Sell
3. List on the Market
4. Change "Sell on Market" to "Return to Storage"
5. List All