Need expert opinion on cannon ball

[Rooter]

I received this cannon ball as a present from a relative who is a long time civil war collector. It was dug in PA. I believe it to be a Confederate 3" solid shot. It's diameter is 3 1/8" and it weighs approximately 4 1/2#'s. It seems to have the proper mold cast line around it. It just seems different the other shots I've seen. It has some damage which may be due to impact. It seems very porous. It's non magnetic but doesn't seem to be lead. It was perfectly round before the damage. It's also not soft like lead and you can't make a mark on it. I am looking for some expert opinions. Thanks in advance for sharing your knowledge!

[Rooter]

Does anyone have an opinion?