What you need is a #54 drill bit, forget about places like ACE hardware you should purchase this online and buy at least 6 of them

These very small wire gage drill bits are very easy to break so what do you need to do is keep your drill very very steady unless of course you use it with a drill press, which makes it a lot easier

When you are drilling do not go all the way through.

Drill about halfway into the sight blade from one side then reverse and try to drill the rest of the way from the other side this will be easier on the drill bit and give you less chance for breakage

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