No they will not hurt barrel. We have been firing tens of thousands of rounds no damage to our M1s or other bbl's , our M1 a Garands are just as accurate as they were 20 years ago spot on very very accurate . Tracer is big wives tail. They dont even light till there about 100 yards out I'm average we probably put 500 rounds tracer ball and another 1000 rounds of regular non tracer through the barrel every year , no problems. The thing you should watch out for is the corrosive ammo (corrosive primers). we reload our own brass , use the tracer heads bought online or gunshows. no problems .email if u need info.