Whenever you are in a civilised location you can make an Influence Test to attempt to acquire a piece of Wargear. The Value of the Wargear determines the base DN of the Influence Test, which is modified by the Rarity of the Wargear (see Rarity on p.206).
To make an Influence Test to obtain Wargear, you must share at least one Keyword with the piece of Wargear.
For every matching Keyword beyond the first, you gain +1 bonus die to your Influence Test.
If you fail the Influence Test, you may spend Wealth to add Icons to your result. Each point of Wealth you spend earns one Icon.
If you roll a Complication on the Influence Test, you lose one Wealth.
Ammo is acquired differently to other Wargear, explained fully on p.229. Whenever you requisition a ranged weapon it comes fully loaded, with a single additional Ammo.
You may make one Influence Test to acquire Wargear each session, and one Influence Test to acquire ammunition each session. Whether you choose to roleplay the process of finding a seller and negotiating a price, or just roll and move on, the act of acquiring Wargear takes considerable time.