Author Topic: Barrel pin holes wandering off  (Read 14957 times)

Offline Scota4570

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Barrel pin holes wandering off
« on: November 21, 2014, 04:00:19 AM »
I have done several barrel pin retaining holes lately.  I use a milling machine and milling vice.  My mill is an old Index brand, about 3/4 the size of the Bridgeport I really want.  I usually go  1/8" for the hole and pin.  Anyway, no problem hitting the right spot on the retainer under the barrel.  It must be running parallel with the top flat of the barrel, I index off that.  The trouble is after going through the metal it goes off to right field on the back side of the hole.   

What the heck?  There must be a trick.  What am I missing?  Maybe drill from both sides using the drill press and spike method and meeting in the middle? 

Meteorman

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Re: Barrel pin holes wandering off
« Reply #1 on: November 21, 2014, 04:13:25 AM »
Lots of ideas here:  http://americanlongrifles.org/forum/index.php?topic=32805.0

Initially about drilling thimbles, but the theories hold for underlugs.
/mike

Offline Jim Kibler

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Re: Barrel pin holes wandering off
« Reply #2 on: November 21, 2014, 05:36:58 AM »
Eighth inch is huge.  I use 1/16".  Drill all the way through the wood only.  Replace barrel and drill through lug with a hand drill.  Setting up on mill or drill press is great for placing initial hole in wood.

Offline Curt Larsen

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Re: Barrel pin holes wandering off
« Reply #3 on: November 21, 2014, 04:29:29 PM »
I make mine 1/16" like Jim.  I do them by hand using one of Tom Snyder's drilling jigs to line up my holes on each side.  You can also use Dave Rase's tool.  I use a pin drill to drill my holes in the wood from each side to make sure they match up.  Then I clamp the barrel with underlug in and use the pin drill for that too.  It takes a while and your fingers may get tired but as long as you have a sharp drill you can go through brass of steel without too much hassle.  Using this drill jig on a pre carve is a bit tricky though.

Offline huntinguy

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Re: Barrel pin holes wandering off
« Reply #4 on: November 21, 2014, 05:02:06 PM »
my guess would be that the slug of the lug is coming out and pushing the drill off course. After you drill through the lug stop and remove the slug. (by slug I mean the little disk that will come when the drill goes through.) You might try to make sure your drill is very sharp and or change the drill point angle.

I have seen this happen at work on occasion when someone decides to stack material and drill. the slug breaks loose and just spins not letting the drill cut.
Anything worth shooting is worth shooting once.

Okefinokee Outlaw

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Re: Barrel pin holes wandering off
« Reply #5 on: November 21, 2014, 05:02:12 PM »
I'm a newbie and have only built a couple of Chambers' kits, but if the hole wanders a bit, I don't think it hurts the functionality, correct?  Or am I missing something?

Offline D. Taylor Sapergia

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Re: Barrel pin holes wandering off
« Reply #6 on: November 21, 2014, 07:48:45 PM »
If you are cutting molding lines down the forearm, having the pins out of alignment can be a problem.  Other than that, it is just a little flaw that irritates some.
I drill my holes for barrel retaining pins to fit a finishing nail that measures .073" with a #46 drill bit.  I use 1/16" welding rod pins for thimbles.  I drill my holes all in one go using the highest speed my drill press will generate, and advance slowly, clearing chips frequently.  I just did the two barrel pins on a Jaeger build yesterday, having marked both sides of the stock for location, and the drill came out exactly on the marks on the far side in both cases.  A sharp drill, and a light touch, and high speed, is the ticket, for me, at least.  Oh, and I drill the forearm while it is still square, when I'm building from the plank.
D. Taylor Sapergia
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Offline Pete G.

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Re: Barrel pin holes wandering off
« Reply #7 on: November 22, 2014, 02:27:08 AM »
It happens to everybody, some more than others. The good thing is that nobody can see both sides of the stock at once anyway.

As others stated, 1/8" is too large for a barrel pin. A 1/16" hole is much less noticeable and plenty strong enough.
« Last Edit: November 29, 2014, 04:24:46 PM by Pete G. »

Offline Mark Elliott

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Re: Barrel pin holes wandering off
« Reply #8 on: November 22, 2014, 02:47:28 AM »
I use 1/16 and 5/64 music wire for pins.   I usually use a drill press with a stop at the back for the barrel to locate the barrel and stock properly to drill for the pin.   As long as I go slow through the tennon,  it doesn't drift that much.   I do need to clamp the work in place (to the table and the stop) to make sure the drill goes where I want.    I usually position the stop so that the hole is drilled roughly in the center (horizontally) of the tennon and just a hair under the barrel.   Once you hit the metal, you need to come to a stop and let the bit get a good start in the tennon.   Use a light touch and feel your way.   Now,  this is not going to be as accurate as Jim's method.    I  would use that method if I was going to have forearm moulding.   Also,  for forearm moulding, you are going to want to carefully layout the pin locations vertically so that they fall in a straight line.    Ideally,  the pins should be falling in the moulding grooves.   For most of my plain southern rifles,  it makes no difference where the pins fall.   

Offline flehto

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Re: Barrel pin holes wandering off
« Reply #9 on: November 22, 2014, 04:43:23 PM »
As Taylor said.....sharp drill which is properly sharpened, a high spindle speed and  a very light touch , especially when the drill contacts the lug. A high speed drill press is the way to go. Lining up the drill w/ the "dimple" is all important to eliminate "walking holes.".

I use .062 music wire which is not noticed as to the forestock  molding.,,,,whether in it or slightly off of it.

The 1/16 hole is drilled through the stock and lug all in one swoop.....same goes for the RR pipe lugs.

I don't try to locate the 4 bbl lug holes "in a line".  W/ very thin "webs", the bbl lugs aren't that high and the pin holes out of necessity, are nearly touching the lug base. There's' just no "room" to line up the pin holes.

Tried using one of the drill jigs but found it to be a lot less accurate and much more time consuming than my method.

Kinda hard for a 1/8 drill to wander and makes one think that the stock isn't parallel w/ the spindle.....whether clamped or not.

But whatever "way" gets the job done, is the way to go......Fred    
« Last Edit: November 22, 2014, 04:58:11 PM by flehto »

jamesthomas

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Re: Barrel pin holes wandering off
« Reply #10 on: November 22, 2014, 05:34:38 PM »
 Yep, a 1/8th inch size pin is to big, I like 1/16 inches like the other guys.

Offline T*O*F

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Re: Barrel pin holes wandering off
« Reply #11 on: November 22, 2014, 07:11:24 PM »

Quote
The 1/16 hole is drilled through the stock and lug all in one swoop.....same goes for the RR pipe lugs.
Maybe you guys don't inlet as close as I do, but when I drill wood and pipe lugs in one fell swoop, the metal mushrooms on the back side of the lug as the drill breaks thru.  That little mushroom prevents me from removing the pipes without tearing out a chunk of wood, so I quit doing it that way long ago.  I spot my holes on both sides and drill until I hit the lug, leaving a small mark on it.  Then I take it out, drill the hole, re-install the pipe and run the drill back thru to line the holes up.
Dave Kanger

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Offline Jim Kibler

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Re: Barrel pin holes wandering off
« Reply #12 on: November 22, 2014, 11:38:21 PM »
Sharp bits and reasonable feeds and burs on the opposite side of the hole aren't a problem.  All I've ever gotten was maybe a bit of a scratch.  Or, like you suggested, just drill from both sides...

Turtle

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Re: Barrel pin holes wandering off
« Reply #13 on: November 24, 2014, 05:07:42 PM »
My problem with barrel pins is mostly mental! I take a week to slowly inlet a lock or patchbox and then rush drilling the barrel pin holes-sometimes with bad results. I just don't take enough time and care for some reason?
                                             Turtle

blackbruin

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Re: Barrel pin holes wandering off
« Reply #14 on: November 28, 2014, 04:15:34 PM »
One thing I found out is don't use cheap Chinese drill bits!  But if I had asked more questions to the person helping me I wouldn't have had to figure that out on my own.....

Offline Dphariss

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Re: Barrel pin holes wandering off
« Reply #15 on: November 28, 2014, 05:54:45 PM »
I have done several barrel pin retaining holes lately.  I use a milling machine and milling vice.  My mill is an old Index brand, about 3/4 the size of the Bridgeport I really want.  I usually go  1/8" for the hole and pin.  Anyway, no problem hitting the right spot on the retainer under the barrel.  It must be running parallel with the top flat of the barrel, I index off that.  The trouble is after going through the metal it goes off to right field on the back side of the hole.   

What the heck?  There must be a trick.  What am I missing?  Maybe drill from both sides using the drill press and spike method and meeting in the middle? 

Shotgun approach here. No set way to do this.
Cut a groove in the underlug for the pin or use a staple. OR use a NEW drill bit and spin it at something around 1500 rpm clear chips at least every 1/2" or less. Drill should not run off that much. Use careful, light pressure when it starts drilling the underlug. Is the underlug "square" with the barrel side flat? If its angled or has much roughness or divots it can be a problem. The support the drill gets from the wood should prevent its running off when it starts into the underlug.
If the head is adjustable for angles be SURE the quill of the mill is 90 degrees to the work in all respects.
I use 3/32 pins if I use pins.
Dan
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Offline Dphariss

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Re: Barrel pin holes wandering off
« Reply #16 on: November 28, 2014, 05:56:54 PM »
QUALITY drill bits. I forgot to mention that though someone did above.

Dan
He who dares not offend cannot be honest. Thomas Paine

Offline Bob Roller

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Re: Barrel pin holes wandering off
« Reply #17 on: November 28, 2014, 07:09:13 PM »
QUALITY drills! You will destroy every Walmart and the rest of these tool sellers that specialize in the low end of everything in existence.The sweat shops and prisons of Asia will have to lay off prisoners.

Bob Roller

Offline okieboy

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Re: Barrel pin holes wandering off
« Reply #18 on: November 28, 2014, 07:50:52 PM »
 Using a new good quality drill (about $1.50-2.00) for each new gun is a good investment. Taking the time to withdraw the drill bit often (machine shops call it peck drilling), especially as the hole gets deeper will also help.
Okieboy

Turtle

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Re: Barrel pin holes wandering off
« Reply #19 on: November 29, 2014, 01:53:18 AM »
I saw a gun building video a while ago where the instructor said to drill to make a mark on the lug, remove the barrel, drill the hole, replace the barrel and then drill the rests of the way. seemed like too much bother, but not I'm not so sure.
                                            Turtle

Offline kutter

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Re: Barrel pin holes wandering off
« Reply #20 on: November 29, 2014, 07:56:26 AM »
I drill them from both sides. I use a center point locked in the drillpress vise, the same idea as when drilling for the tang screw. A short bit drill no longer than needed to do the job. Extra length just bends & flexes.

I drill down to and through the lug from one side. Flip it over and drill the other side down to the lug, again using the center point placed in the already drilled pin hole this time.
The outside pin holes are then always right where I want them.
They usually meet and line up so the pin goes right on through. 

If if needs a little help, I redrill from the first side I cut and go through the lug and on through into the hole on the other side but short of exiting the side. That clears the path and joins the two so the pin will slide through.
I like 1/16"d welding rod for pins. Sometimes use brass.

Offline B.Habermehl

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Re: Barrel pin holes wandering off
« Reply #21 on: November 29, 2014, 03:39:37 PM »
Cutter, please don't take this wrong, I absolutely do not recommend using brass for pin stock! In my opinion it is by far the worst choice. Steel is the way to go. I really prefer music wire stock. Lots of builders use cut off finishing nails, I like music wire because the ends of the pin will never mushroom while driving them in or out, tearing out chips of wood. I recently discovered a good source of wire at my local big box home store. 16 inch lengths ment to hold up insulation, sold in bundles. About 5/64 dia. A abundant supply for a pretty nominal price. BJH
BJH

Offline WKevinD

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Re: Barrel pin holes wandering off
« Reply #22 on: November 29, 2014, 05:32:01 PM »
OK I'll throw my two cents worth in.
I use 3/32 steel welding rod for barrel pins and a new bit, straight thru. I clamp my still squared up stock and barrel in my drill press vice making sure the barrel flat is pressed evenly on the vice face, and check for level. Then feed the bit into the wood slowly 'till I feel the tab, raising the bit and clearing chips regularly until I feel it go thru the other side. Drill sharpness, feed rate and initial drill press set up are important and layout is critical.
I won't drill one side then the other cause I don't trust my abilities to line up perfectly, to many variables to screw up.
For pipes I use the same set-up but use 1/16" pins.
Kevin
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Offline kutter

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Re: Barrel pin holes wandering off
« Reply #23 on: November 29, 2014, 07:28:32 PM »
Cutter, please don't take this wrong, I absolutely do not recommend using brass for pin stock! In my opinion it is by far the worst choice. Steel is the way to go...... BJH

No offense taken,,I use steel pins too (finishing nails).
The brass I use is actually 1/16d brazing rod. Seems tougher than the soft brass pin stock sold for hobby/craft work. I put a bevel on the ends no matter if they're brass or steel  and haven't had any problems. A well fitting punch is a must and at this point in life magnification so I can see what I'm doing!

Don't really know why I ever started using the brass pins. All I can think of was way back I thought the steel pins may rust in place in the wood from handling w/BP fouling or maybe an AF stained stock that wasn't neutralized.
Never had the former problem and don't use the latter. So it's just an old habit I guess.

Offline Dphariss

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Re: Barrel pin holes wandering off
« Reply #24 on: November 30, 2014, 04:02:02 AM »
I use piano wire. Its a soft spring temper and will not deform or bend easily.
I also buy good drill bits usually TiCN or some other high tech coating. Do not use "oxide" I.E. "blued" drills they won't clear wood chips as well as polished or high tech coating will. But one cannot buy the better drills for 2 bucks.
If you have a mill or drill press then start the hole with a small center drill at least 1/2 (the drill) diameter deep or deeper if the center drill's small diameter is at or under the finished diameter.

Dan
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