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When applied to a submachine gun, the mod greatly increases the weapon's total magazine size while reducing reload speed.
|Submachine gun||Learned from scrapping||Low (15%)|
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- The large drum mod may be crafted and applied to a submachine gun at a weapons workbench if the relevant plan is known. The mod can only be learned from scrapping submachine guns.
- Loose large drum mods may be randomly sold by Responder, Raider, Brotherhood, and Free States vendors. Loose mods can also be found randomly in various locations or earned as quest rewards in the Toxic Valley, Ash Heap, or Savage Divide.
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