Fastening the bumper does work.
Originally Posted by Dewok82
You are only partially correct in your theory. The shape of the back of the level 10 bolts, which are a bit different than the level 7 bolts, are the biggest reason the bumpers shred. The bumper material pushes outward when the bolt hits it. The inner diameter of the bumper is held in place by the inside edge of the bolt. If you have a look at the powertube of the valve, you will see a small groove at the base of the powertube. When the bolt is back, and the bumper is compressed, some of the bumper fills this void. The bumper is literally torn as it is pulled outward while the inner material is held in the void at the base of the powertube. By gluing the bumper to the valve, you are reducing the stretching and movement of the bumper and prolonging its life.
Except for the Automag in front, its usually the man behind the equipment that counts.