A 3-position competitor I shot with many years ago, refused to purchase a match rifle or have one made up. He used an old 722 Rem, chambered in .222. That was an 'older' light barreled sporting rifle of years gone by.

Trouble was, it shot as well as any match rifle, primarily due to the "2" long cylinder of lead" he had attached to the barrel with set screws.

Initially, he attached it on the muzzle at first, firing a known accurate load for the rifle, then repositionied, it and shot again, until he accidently achieved even better, 1/4MOA accuracy, which exceeded the rifle's normal barely 1/2moa. In 1973 - 1/4moa consistantly, was BR accuracy, and he got it, not with a Hart or Shilen match-grade barrel, but with a factory Remington lightweight floated barrel with a 'weight' attached which seemed to perfect the barrel's harmonics.

The flashlight can do exactly the same thing - but, you must find where the rifle wants it to be. Will it postively, absolutely work? - maybe.