If you go back to the gun magazines/Gun Digest of a few years ago there will be articles on how great and what a wonderful new invention was the threaded weight on the muzzle end of Winchester/Browing rifles. Superior accuracy was achieved by "tuning" the barrel vibrations by screwing the weight (damper) in or out to achieve tremendous accuracy. The circumference had numbers so you could do trial and error to get the number for a particular load. A wonderful thing to tinker with and all the experts wanted one----they don't seem to be offered any more. I never saw the article telling us why this went to the great dustbin in the sky. Like saboted .22 bullets in .30 cases, this will come back into vogue in another 20 years or so. Wonderful but impracticle ideas are great and never go away.