Don't be the guy we post photos about in my Marlin 39A group showing how F'ed up the screw holes are and how they ruined the value of the rifle.
Take it to a gunsmith!
I'm a retired machinist and a gunsmith. I would do that indicated in on my mill, NOT in a drill press. I wish I could go around and destroy all drill presses because of the garage hack jobs I've seen. And BTW, machine shops, and hopefully most gunsmiths, don't buy their drill bits at Ace. Ace drill bits are junk! Any drill bit from any big box store is junk! We buy our bits from tool supply houses.
If the hole you drill does NOT look factory, you just ruined that rifle!!!
The steel is not hard. But it is tough and will snap a small tap in a heartbeat if it's not done correctly using a quality tap and the proper tapping fluid.
And if it is a blind hole, you'll probably need at least two taps, maybe three. Sometimes you can't get a tapered tap to engage in a blind hole so you need a gun tap or a blind hole tap BUT they may need to be ground a bit to get that engagement. I rarely buy blind hole taps and grind my own from a "regular" tap. But you have to know how to grind a cutting edge(s) on a tap to do that. I do that because blind hole taps rarely cut enough threads in a short blind hole.
We won't get far into drill bit sizes and percentages of tap engagement, but it is okay to "sometimes" step up a size in drill bits to get less tap engagement. Suggested tap drill sizes are roughly 75% thread engagement.
All that said, take it to a gunsmith. It really isn't that much money to have it done correctly. Which means a correct tapped hole AND in the center of the receiver. If the hole isn't centered, you'll have gun owners from now until the end of time calling you names. LOL!!