The .25 Pocket Auto traces its lineage to the 6.35mm Browning ACP of the early twentieth century, a cartridge designed from its inception to fit inside the smallest possible semi-automatic pistol. By 2200 it occupies the same niche it always did: the round you carry when carrying anything larger would be noticed. In GLMZ's layered social architecture, that means it is the ammunition of mid-tier office workers who can't afford security contractors, Tessera Corponation data clerks who travel through mixed-access transit corridors, and the better-dressed residents of Tier 2 districts who want something in a coat pocket that won't print through the fabric scanner at an Arcturus checkpoint. Slagworks and several smaller manufacturers still produce it in brass-cased standard, and a caseless variant exists but never gained significant traction given the round's primary use case in legacy micro-pistols that predate caseless chambers.

The .25 Pocket Auto is not taken seriously as a defensive cartridge by anyone with access to alternatives. Ballistic testing in 2200 rates it statistically below the .22 Short-Long in terminal effectiveness against augmented targets — the proliferation of subdermal trauma plating among even mid-tier civilians has rendered it nearly decorative in some threat scenarios. Its defenders, and there are many, argue that the point was never to stop a fight but to start a conversation about whether starting one was wise. In the warrens of GLMZ's mid-access zones, the sight of a .25 pocket auto coming out of a sleeve is still enough to change the math.