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Author Topic: Drill Bit Sizes  (Read 1483 times)

Offline MissouriKid87

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Drill Bit Sizes
« on: December 14, 2017, 01:51:26 PM »
Does anyone have the drill bit sizes for the following calibers: .31, .44 and .72 by chance? The .31, .44 are pistol and .72 is rifle.
"You cannot invade the mainland United States. There would be a rifle behind every blade of grass."- Isoroku Yamamoto, Japanese Admiral- December 7, 1941

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Offline PetahW

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Re: Drill Bit Sizes
« Reply #1 on: December 14, 2017, 06:01:51 PM »
.

Presuming you want to drill a barrel prior to rifling it, subtract the depth of the rifling planned x 2 (both sides or the bore), then use this chart to find the drill bit number.

http://bobmay.astronomy.net/misc/drillchart.htm


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« Last Edit: January 24, 2018, 10:04:16 PM by PetahW »
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Offline Lonewolfe20

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Re: Drill Bit Sizes
« Reply #2 on: January 24, 2018, 03:23:17 PM »
That was a great page I just printed it out
Thanks PetahW
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