Most military bimetal bullets are a mixture of soft iron, not steel, and copper. Will they wear the lands faster than copper or brass? Probably but I don't think that I can shoot enough of them to see a difference. Do I shoot them through my long range 308s? No but I do use them in my 300 Blackout and I shoot a lot of them without seeing a difference in accuracy but I only shoot it to 200 yards. David