It depends on the county, in San Francisco, Oakland, and LA, you can't as far as I know. There may be others but I am not aware of them. Your going to have to search the specific county and city laws to be 100% sure. It is okay to ship it on the state level though.
I'm gonna stop you right there, you just said an AR-15 is a high-powered rifle. It is obvious you don't know anything about guns and I shall ignore anything you say from this point on.