Systems for leveling a firearm receiver and aligning a scope to the receiver are precisely fabricated and assembled to maximize accuracy, including high sensitivity spirit levels. A bar assembly with a high sensitivity spirit level is received in the receiver with the bar in direct contact with the receiver rails. The bar may directly contact the full length of the receiver rails. A plate assembly includes a lower plate for connection to a bench rest, an upper plate for connection to the receiver, and a mechanism to pivot the upper plate relative to the lower plate about a pivot axis for windage adjustment. Methods of use are disclosed.