On the contrary, it is a very positive thing. Mostly beneficial for rifles without the really thin sporting barrels. Properly done, it will help the rifle shoot more consistently, if not more accurately. It all depends on how the rifle is currently sitting in the stock. It can't hurt to do. Make accuracy worse? Maybe if you bed a rifle and freefloat the barrel of that rifle at the same time, when the barrel was previously not free floated. Sometimes with the thinner barrels, freefloating makes the accuracy worse. These barrels need a pressure point out towards the end of the stock to dampen the vibrations for more accurate shooting. No way to know except to try these things.
