I have some once fired .223 brass that has a small ding on each one. I believe the ding is from deflector on the AR-15. Is it still ok to reload?

Yes. Just run it through the sizer.

Thanks. I thought it should be ok, but this is my first go at reloading rifle, so I thought I would get another opinion. The ding does remain after sizing.

As long as the resized/reloaded brass/round chambers, it will be fine. The ding will fire form out.