Silencers generally do not affect velocity unless wipes or mesh are used, then only when the bullet contacts the rubber wipes or metal mesh. Most good modern suppressors only use baffles that are machined to have an inside diameter of about 50 thousands of an inch greater than the bullet diameter. The range of the rifle is only affected if subsonic ammunition is used instead of standard supersonic ammunition. A suppressor with baffles will actually raise the velocity of the bullet as it passes through. This is because the propellant gases will jump to over 5000 fps and are still contained inside of the suppressor and push a little bit on the bullet as it passes through. This slight increase in speed does not happen at all in suppressors equipped with wipes. If the barrel is ported, then velocity suffers, but not always a great deal. Porting allows some of the propellant gas to vent into the back of the suppressor, and helps reduce sound. The word “silencer” is a legal term in the USA,