Disclosed herein is a golf ball comprising one or more fast-chemical-reaction-produced components, such as a component which comprises a reaction injection molded polyurethane material. A process of making a golf ball by forming at least one core and/or cover component of the ball by mixing two or more reactants that react and form a reaction product with a flex modulus of 1 to 310 kpsi, with a setting time of about 30 seconds or less, the component having a thickness of at least 0.01 inches and a mold release time of 2 minutes or less is also disclosed. In one preferred form of the invention, excess polyurethane from forming golf ball covers is recycled by using it to form golf ball cores.