Firearm stabilizing apparatuses may include a device mounting assembly configured for securement to a support. A reel assembly may be supported by the device mounting assembly and configured for attachment to a firearm. The reel assembly may include a reel line configurable for extension and retraction within a vertical plane. The device mounting assembly may be configured to facilitate movement of the reel assembly within a horizontal plane when the device mounting assembly is secured to the support. The reel assembly may be selectively configurable in an adjustment mode and a locked mode. The reel assembly may be configured to selectively facilitate positional adjustment of the firearm within the vertical plane in the adjustment mode and securement of the firearm at a selected position within the vertical plane in the locked mode of the reel assembly when the device mounting assembly is secured to the support.