I'm sure you've found a solution by now, but I had this problem too, even with pre drilled holes! I then switched to a diamond/square shape deck screws, adjusted the bit, and they went in beautifully.So is there a trick to using them? I'm swearing at them at the moment as they won't go in with my drill or my hammer. Start them with the hammer and they will screw in partway with difficulty. I've pounded them in the rest of the way, now I have 2 that I can't even pound in. I'm wishing I had my 30+ old electric drill but it was stolen, I think more powerful than this battery charged Ryobi . Taking a break cause my arm is worn out.