You will get corrosion between the aluminum rail and steel rings (if you go that route), but it will take a long time if the rifle is kept where the humidity is low. I'm no expert on metallurgy, but I believe the corrosion we sometimes see between dissimilar metals is known as electrolysis. Has something to do with electron counts in the outer valence shells of the metal's atoms. If anyone knows for sure, please correct my lack of knowledge. I took Freshman Chemistry twice in college; got a D- both times but the second taking satisfied my Science requirement. The first one, at the University of Arizona in 1977, would not transfer to Virginia Tech in 1985...