[John Rogers]

For hardened steel like your bolt you would want about 1500 RPM on the drill bit and some drill lube that also removes heat and melts. I generally use Crisco for that unless it is tool steel then I use a special heat absorbing paste. I don't know what speed your drill turns so that could be the problem?

Time to visit Harbor Freight and get one of their drill presses, I use one of their floor models and have almost never used a hand drill for holes since. The advice for a small flat spot is correct but make sure the bit is lined up to go straight through the bolt. Good luck.