58 also includes a plastic plunger bumper 64 reciprocally located in the open aft end portion 66 of the buffer body 60 this plunger bumper 64 is secured into place for reciprocal movement within the rearward portion 66 of the buffer body 60 by a pin 68 that fits through a slot 70 in the plunger bumper 64 so that an enlarged tapered rear bumper portion 72 extends outward beyond the aft end portion 74 of the buffer body 60 under certain circumstances that will be hereinafter described the flat rear plunger bumper portion 76 strikes a portion of the spacer 59 or the rear surface 50 of the receiver extension 20 when the buffer body 60 is in the full recoil position the buffer assembly 58 also includes three solid cylindrical tungsten weights 78 80 and 82 located within the hollow interior 84 of the buffer body 60 these weights 78 80 and 82 are each cylindrical shaped and have the same exterior dimensions and they are sized and shaped for reciprocal movement within the hollow interior 84 of the buffer body 60 when the plunger bumper 64 is secured in place by the pin 68 with part of its smaller diameter cylindrical portion 86 located in the aft portion 66 of the interior 84 of the buffer body 60 the two weights 80 and 82 that are separated from the plunger bumper 64 by the weight 78 have respective identical circular cross section cylindrical blind holes 88 and 90 that centrally are located in the respective surfaces 92.