At 1.450” wide and 9.5” long, the 1581 action is the largest of the Surgeon line of actions. It comes with a full-length 30 MOA integral 1913 picatinny rail, a huge .450” integral recoil lug, and a large 1-1/8”x 16 tenon thread, which requires the use of a 1.350” diameter barrel.
The 1581 uses a removable trigger hanger that was built for Remington 700 style triggers.
In the middle of the left bolt raceway is an anti-jam rail. The purpose of this rail is to prevent a round from lodging in the raceway when single loading the rifle through the ejection/loading port.
Just like the Surgeon short and long actions, the 1581 has a side-mounted bolt stop that is shrouded to help prevent accidental releasing of the bolt.