In nearly all cases (excluding some machine guns), the attachment applies a flat 50% increase to the magazine capacity, which often results in overlarge or understated capacities for real magazines. In many cases, the extended magazine is a fictional invention or some other gun's magazine stuffed into the gun.

Somewhat interestingly, the extended magazine attachment in WWII always changes the magazine model (in contrast to several CoD games).

Some of these weapon variants also change the weapon inspection animation, sometimes to be more humorous. A few cases of borderline weapon distinctions remain as subsections to make management easier. As a result, on this page, firearms identified only in weapon variants are placed as subsections of the original weapon's section. Many of these weapon variants feature model changes in addition to finish changes, often completely changing the weapon's identity. WWII uses weapon variants as a part of its multiplayer customization system, much like Advanced Warfare and Infinite Warfare, though WWII’s variants are purely cosmetic and do not change the weapon's statistics. 3.18 Tokyo Arsenal Experimental Submachine Gun.