Turn in place: chest-led rotation, 45 degree steps, head IK toggle player_model.prefab - head Gain 1.6->0.5 / Max 30->9.1, chest Onset 14->0 / Gain 1.0->2.2 / Max 20->28, TurnSpineLowerShare 0.45->0.85: the chest now carries the aim from the first degree of offset instead of the head absorbing ~19 degrees first, which is what caused the gun/aim disparity. PlayerModel.Turn.cs - turnminstepangle default 90->45: only the 90 clip was reachable so every commit swung a full 90 regardless of need, and this also drops the re-commit stability floor from 45 to 22.5. PlayerModel.Ik.cs - added pm_headik static (default on, no behaviour change) to disable the head look IK, which proved the head/gun misalignment and idle/ADS snap come from the IK rather than the animation export. DevTurnTuner.cs - on screen Head IK button plus L hotkey so that toggle is reachable in play without the console.