A variable mass cap 20 for a shock imparting implement grip has a butt element 22 connected to a tubular portion 24 constructed to receive a selected mass 26, 28. The tubular portion 24 fits snugly within a recess 34 of a body 32, and is retained therein by the engagement of an annular ridge 36 with a first annular groove 30 disposed in an outer surface of the tubular portion 24. In an alternate embodiment, threaded portion 31 is received by and engaged by a corresponding threaded recess 34. The cap 20 is mechanically secured to the body 32 for providing a grip with a variable mass.