Thanks for all the advice. Unfortunately, time being a consideration, I purchased a short auger bit locally. It is already dull from one nail. I don't think I will buy Irwin again. I might be able to sharpen the bit, or at least remove the burr from the nail. I also had to buy a long one as I ran out of hole space in the top plate. I ended up buying a long Greenlee bit just for that. It does a great job! Before my next electrical job I'll be ordering the short Greenlee bit.