How to Increase Ammo Capacity in Borderlands 3


Ammunition can run out very fast in Borderlands 3. You’ll have to constantly switch between different weapon types as you’ll probably be blowing through all your ammo.

Just like in Borderlands 2, you can upgrade ammo capacity pretty easily, and early on in the game. You can do this with SDU’s, also known as ‘Storage Deck Upgrades’.

In this guide, we’ll show you how and where to upgrade ammo capacity in Borderlands 3. For more Borderlands 3 Guides & Best-of content for PS4, PC and Xbox One, make sure to check out our dedicated area here

Increasing Ammo Capacity

To increase your Ammo Capacity in Borderlands 3, you’ll need to purchase Storage Deck Upgrades (SDU’s). These can be acquired from Marcus Munitions, compared to Borderlands 2 where we used to obtain them from Crazy Earl. 

increase backpack size borderlands 3
SDU’s at Marcus Munitions

You can find Marcus Munitions in Sanctuary. So you’ll have to be out of the starting area at least. You’ll also need to have done a small side quest which Marcus will give you, which involves putting out fires.

Purchase Ammo Capacity

You can puchase SDU’s for every weapon type. The cost for the first tier is $1000 in-game cash. With the cost getting higher with each tier. You can also purchase inventory slots, grenades and bank slots from Marcus.


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