 Chalker is credited for inventing and developing a tactical rifle and submachine gun single-point sling known as the Chalker Sling while at SEAL Team Six.The Chalker Sling attaches the long gun to the shooter via a harness which enables the operator to quickly transition to a secondary weapon or perform another task while using both hands and keeping the weapon in a close-ready position as the weapon "hangs" from the chest, leaving just enough slack to be able to quickly bring it to firing position with little effort.Since retiring from the Navy, Chalker has authored six books, three fiction and three non-fiction with Kevin Dockery about life as a Navy SEAL.