[NAILER341]

The 100-400 lens has F 4.5-5.6 and the F 4.0-5.6. Those are both too high in the F stop arena to take strong night shots with no flash.
Look into a F 2.8 lens or lower.
If you have a 50mm lens, check the F on that.

All of the photos I have taken are F 2.8 or lower so that you can keep the ISO at a level that isn't too grainy, and keep the speed at 150+.

I think the problem for you Vern is too small of a lens aperture. Borrow a 2.8 lens and try it out.
I think you'll like the results much better.