The Impact 737 action features an integral 20 MOA picatinny rail and recoil lug, a rugged bolt stop design, and a trigger hanger assembly for ease of trigger installation and maintenence.  The system's interchangeable barrel and bolt system across the product range makes for the most flexible and user serviceable precision rifle system available.  It is no wonder that it is the preferred action of precision shooters worldwide.  This is a short action with a bolt for .223 family of cartridges including .222, .204 Ruger, .300 Blackout, 17 Remington, etc.