Author Topic: Drilling Tang Bolt Holes  (Read 1099 times)

Offline Bob Gerard

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Drilling Tang Bolt Holes
« on: December 17, 2023, 03:30:53 PM »
Hello,
I am curious how builders here drill the barrel tang bolt holes.
One way which I am familiar with doing is to line-up the drill  (I use a drilling jig) and make one long pass straight through from top of tang into the trigger plate.
Another way I saw in a tutorial here (I believe Runastav showed this method?) was to go at it from both top and bottom, drilling down through the barrel tang to mid- depth, and then drilling up from the trigger plate and meeting the tang bolt hole. This way seems like the bolt holes should be perfectly located. Also seems less prone to missing center on the plate.
Any feedback would be great and helpful!
Thank you


Offline Cody Tetachuk

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Re: Drilling Tang Bolt Holes
« Reply #1 on: December 17, 2023, 04:45:21 PM »
Drill a locating pilot hole in the proper location in the tang and the trigger plate where you want the bolt to go in and where you want the bolt to come out, then mount a "spike" in the drill press table perfectly aligned with the drill bit, set the "spike" in the trigger plate hole and drill the tang hole at least half way through (you can go all the way until the bit hits the trigger plate if you want just be sure not to let the bit touch the end of the locating spike). Then flip it over putting the spike in the tang hole and drill back from the trigger plate until the holes merge. Perfect hole, perfect alignment every time.
« Last Edit: December 18, 2023, 12:56:33 PM by Cody Tetachuk »

Offline Bob Gerard

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Re: Drilling Tang Bolt Holes
« Reply #2 on: December 17, 2023, 05:24:21 PM »
So you also drill down from the top, and up from the bottom, and meet in the middle. Thanks!

Offline Cody Tetachuk

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Re: Drilling Tang Bolt Holes
« Reply #3 on: December 17, 2023, 05:35:57 PM »
Yes but it is imperative that you have a locating spike to end]sure that the holes come together as one. Without that locator, the holes likely won't align in the middle and you can have real mess on your hands.
« Last Edit: December 18, 2023, 12:57:13 PM by Cody Tetachuk »

Offline Bob Gerard

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Re: Drilling Tang Bolt Holes
« Reply #4 on: December 17, 2023, 05:47:06 PM »
I have a drilling jig made by Robert Boggs that does that.

Offline Eric Krewson

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Re: Drilling Tang Bolt Holes
« Reply #5 on: December 17, 2023, 05:48:11 PM »
My fancy drilling spike, a cross-slide vise with an arrow field point in the vise. It works well and can be adjusted to line up the drill bit. I am drilling a clearance hole through the wood after tapping the trigger plate, hence the wood bit.

 

Offline Spalding

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Re: Drilling Tang Bolt Holes
« Reply #6 on: December 17, 2023, 05:50:07 PM »
Thatís what I do also. Center punch tang and trigger plate. Set it up in the drill press with the jig and drill a pilot hole through the metal tang, flip it over, and drill pilot hole in trigger plate.
Flip it back again so tang is up, drill tap drill size through tang and stop when it contacts trigger plate. Flip it over, reposition on spike and drill through trigger plate.
Switch to clearance drill bit, set it up on jig again so tang is up and drill through tang and most of the wood wrist, being careful not to go into trigger plate. Remove the trigger plate and the little wood remaining can be hand drilled.

Bob

Offline Cody Tetachuk

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Re: Drilling Tang Bolt Holes
« Reply #7 on: December 17, 2023, 06:07:03 PM »
Spaldings post reminded me of something else, When tapping the hole in the trigger plate, ALWAYS have the barrel and trigger plate installed as it will be when finished and run the tap through the tang and tap from the top. If you pull the trigger plate and tap the hole in a vice or some such you can get the tap off a bit and the bolt, which has little side to side manoeuvrability, will want to cross thread. If you tap the hole exactly like the bolt will be installed, the bolt will thread in freely and centered in the countersink. This goes for tapping the holes in the lock pate for the lock bolts as well. You may have to buy extra long taps to accomplish this.

Offline smylee grouch

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Re: Drilling Tang Bolt Holes
« Reply #8 on: December 17, 2023, 06:45:35 PM »
I also have one of those drilling jigs. It works great for those tang and lock bolts and barrel and pipe pins. The only problem I ever have is finding long enuf drills and taps when working on larger guns.

Offline Pukka Bundook

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Re: Drilling Tang Bolt Holes
« Reply #9 on: December 17, 2023, 06:54:17 PM »
Cody T,

You explain it so well I had to look twice becauuse I wondered if I had written it LOL!
Seriously,  I thought I invented this way of doing it.  (Again, LOL)
But am so pleased the locator spike is used so often.
Mine is a spike welded to a plate, and clamped to drill press so as to align perfectly with drill tip.

Offline Bob Gerard

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Re: Drilling Tang Bolt Holes
« Reply #10 on: December 17, 2023, 07:20:09 PM »
Super helpful information as usual.

Offline Spalding

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Re: Drilling Tang Bolt Holes
« Reply #11 on: December 17, 2023, 08:02:24 PM »
Spaldings post reminded me of something else, When tapping the hole in the trigger plate, ALWAYS have the barrel and trigger plate installed as it will be when finished and run the tap through the tang and tap from the top. If you pull the trigger plate and tap the hole in a vice or some such you can get the tap off a bit and the bolt, which has little side to side manoeuvrability, will want to cross thread. If you tap the hole exactly like the bolt will be installed, the bolt will thread in freely and centered in the countersink. This goes for tapping the holes in the lock pate for the lock bolts as well. You may have to buy extra long taps to accomplish this.

Good catch there, Cody, probably the most important thing.

Bob

Offline D. Taylor Sapergia

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Re: Drilling Tang Bolt Holes
« Reply #12 on: December 17, 2023, 09:17:51 PM »
I use the method described by Cody to drill for both the lock bolts and the tang bolt(s).  For a "spike" I use a large centre punch clamped in a two way drill press vise.
D. Taylor Sapergia
www.sapergia.blogspot.com

Art is not an object.  It is the excitement inspired by the object.

Offline Jim Kibler

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Re: Drilling Tang Bolt Holes
« Reply #13 on: December 17, 2023, 09:32:04 PM »
I've used the drill press and spike method before, but when I need to do this anymore, I just use a hand drill.  Mark both sides and meet in the middle.  Start a touch small and then clean up with the right size all the way through.  This actually works quite well.  If you aren't a good judge of things, have your wife or a friend line the drill bit up to a pencil line on the stock.

Jim

Offline elk killer

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Re: Drilling Tang Bolt Holes
« Reply #14 on: December 18, 2023, 03:53:50 AM »
Clay Smith has a great video on drilling those
Grumpy gunsmith on u tube
only flintlocks remain interesting..