 In June 2017, Ruger issued a safety recall on MK IVs for a defective trigger and safety mechanism.If the safety were midway between the "safe" and "fire" positions when the trigger was pulled, the gun could discharge when the safety was moved to the "fire" position.MK IVs with serial numbers beginning with "401" (2017 models) or "WBR" (2016 models) were recalled.