USPSA Divisions in 60 Seconds (BLUF)

Short answer: USPSA runs eight divisions — Carry Optics, Limited Optics, Open, Limited, Production, Single Stack, Revolver and PCC — and the gun already in your safe decides most of it for you. Stock striker-fired 9mm with a slide-mounted red dot → Carry Optics. A 2011, or any pistol wearing a flared magwell, with a red dot → Limited Optics. Anything with a compensator or a frame-mounted optic → Open, whether you wanted that or not. Iron sights on a duty pistol → Production (15 rounds loaded) or Limited. A .45 1911 → Single Stack. A wheelgun → Revolver. A 9mm carbine → PCC.