What is a tracer?
A tracer bullet contains a hollow base or cavity where a pyrotechnic compound is loaded under high pressures. The compound is similar to that used in ordinary highway flares.
The tracer compound is ignited by the burning smokeless powder when the cartridge is fired. Modern tracers will not "burn" your barrel out and doesn't cause any additional wear.
The story of tracers "burning" out your barrel came from the use of corrosive based compounds in their manufacturer before the 1960. Clean your gun thoroughly with warm soapy water after firing ANY military surplus ammunition or surplus tracer ammunition if you are not sure of the manufacturer or date of manufacturer.