Provided herein are bolt carriers, firearms, and related methods, devices, and assemblies. A bolt carrier for a firearm of an example embodiment includes a cam slot configured to receive a cam pin of a bolt, the cam slot defining a cam path along which the cam pin is configured to travel, the cam path comprising a locked dwell, an unlocked dwell, and a transition section disposed between the locked dwell and the unlocked dwell, wherein the locked dwell defines a portion parallel to a first axis of the bolt carrier that is greater than 0.070 inches long.