Putting a radius on the back edge of the interface lessens the initial force needed to start the slide moving.1. The Hogue Handall Junior fits well, as do others.
2. It is not the easiest slide to work.
Use some grease on the slide rails, hammer interface on the bottom of the slide, and the barrel lugs. Shooting the gun, wearing in the mating surfaces and wearing in the recoil springs will make it easier to rack. Proper technique helps a lot: