Vehicle door-mounted adjustable firearm holder

A method of installing a gun mount apparatus on a vehicle door, comprising:

• obtaining a gun mount apparatus comprising an adjustable clamp with at least two opposing paddles, a rotatable locking mechanism, and a sliding rod,
• wherein said sliding rod comprises at least two U-shaped rests configured to support a firearm;
• positioning said adjustable clamp on a door handle of a vehicle door;
• tightening said adjustable clamp onto said door handle;
• adjusting an angle of said rotatable locking mechanism to adjust a position of said at least two U-shaped rests;
• and
• securing said rotatable locking mechanism in a way such that said at least two U-shaped rests are locked in said position.

A system for affixing a firearm to a door of a vehicle, comprising:

• a clamp mechanism configured to attach to a vehicle door handle without permanent modification to said vehicle;
• a rotatable locking mechanism connected to said clamp mechanism;
• and
• an adjustable support member extending through said rotatable locking mechanism,
• wherein said adjustable support member comprises firearm rests configured to hold a firearm in a muzzle-down orientation.