Elongating barrel attachment pin holes

[frogwalking]

I ask your patience as I have asked this question before.  And...you have answered it before.  I did not understand what you told me.  My question was, and still is, how do you elongate the  holes in the tenon to allow for relative movement between the barrel and stock.  The  last time I asked this, someone said to use a jeweler's saw.  I really didn't understand how this was done, but I bought a jeweler's saw and blades anyway, and am still no closer to understanding how this is done.  I found a 1/16 inch rotary file for a moto tool, and that was too hard for me to control.  Now, I have discovered a Grobet, 1/16 inch round equaling file, but it seems Grobet no longer makes these.  So, I struggle along with my 1970 manufacture Grobet round needle file.  I don't get very much elongation using this.  There must be a better way, but I do not know what it is.  Someone please enlighten me, if that is possible.

[Pete G.]

Drill a 1/16" hole at each end of the intended slot and use the saw to remove the metal between them.

BTW don't forget to lube the blade often.

[Long Ears]

I drill my pin hole through the lug and both sides of the stock. I then remove the barrel and clamp it back in my vise. I get my jewelers saw,  thread it into the pin hole and carefully elongate the hole 1/16" each direction being careful not to drift up or down with the slot. Then I take a flat needle file that I've ground down on one side only to slightly under the 1/16 thickness leaving teeth on one side and one edge only. I use this to clean up the slot. Hope this helps, Bob

[Acer Saccharum]

The jeweler's saw really is a great tool for this job....but not 'having seen it in action', you may very well be intimidated by its delicate seeming blades, and how to set it up.

Pete G's suggestion is a good one.

Have the barrel in a vise, with the tenon sticking out horizontal direction, a comfortable distance away from the vise jaws. Set a blade in one end of the clamp of the saw frame, with the teeth to cut on the PULL stroke, then thread it thru one of the holes. Clamp the other end of the blade and then tension the blade. (how you tension the blade will depend on the style of saw frame you have). Run the saw UP and DOWN to saw from one hole to the other. Let the saw cut, do not force it. You may need to back the saw blade thru the slot you just cut so you can cut the other slot.

Try to cut the slot a little undersized, then you can file it out so your pin slides back and forth.

If your slot ends up a little wide, make up a tapered tool that fits in the slot( like a screwdriver blade shape). Hammer the tenon closed onto the tool, and try your pins in  the slot gain. Repeat as necessary.

[Acer Saccharum]

...and don't forget YouTube:

[Ted Kramer]

Using a staple instead of a solid tenon eliminates the need to elongate a drilled hole. Make the staples out of a proper diameter mild steel welding rod, nail, or any suitable material or they can be bought from most suppliers. Drill the pin hole so that the bit just brushes past the bottom flat of the barrel near the middle of the loop and that's it.
Ted K

[Daryl]

Excellent video, Top- tks

[sqrldog]

Be careful installing staples on a thin walled barrel or you'll have dimples in the bore of the barrel.

[flehto]

First off drill the pin hole through wood and lug....the hole in the lug is your starting point. If the lug length is sufficient, drill two slightly undersized hole on both sides of the original pin hole....don't let the holes run into each other. Use the jeweler's saw to remove the webs. Now use a thin file to smooth out the saw cuts....remembering that the important surface of the slot is away from the bbl.

If the bbl lug isn't long enough for the two drilled holes, either use a small cutter in a Dremel or a round needle file to elongate the hole and finish w/ a thin file.....again, the slot surface away from the bbl is the critical surface.

 I "ink" the original drilled hole so it's easier to see when filing the slot. Finally clamp the bbl in the stock and push in the pins....they should go in fairly easy, but if they don't, lightly file the slot surface that's away from the bbl....the slot surface that's close to the bbl can in fact be filed so that it doesn't touch the pin.

This isn't a difficult task, just requires a bit of time and patience.....Fred 

[Ted Kramer]

Be careful installing staples on a thin walled barrel or you'll have dimples in the bore of the barrel.

Good point Tim. On thin walled bbls. use a slotted underlug (Track's UL-TC2 or similar) dovetailed in a shallow dovetail.

TK

[Mike Brooks]

I have used the jewlers  saw as mentioned above for 300+ guns with no problem. I use a #4 blade from TOTW lately. Easy peasy lemon squeezy..

[Turtle]

 I always just rock the drill bit fore and aft in the holes, and use a small needle file to remove the thin webs left at the front and back of the holes. I can't believe the barrel moves and further than this. Any body ever measure it?
                                           Turtle

[B.Habermehl]

The front hole can move almost 1/8 inch depending on the amount of curl in the forend. I allow a 1/4 in slot in the front lug, and each closer lug to the breech gets a smaller slot. The last lug just gets a enlarged hole. I have seen too many split stocks and bent pins due to inadequate slotting of the lugs. BJH

[Turtle]

 Good advice, thanks. Didn't think of making the front lug slot longer, that makes sense.
                                                Turtle

[Meteorman]

I have used the jewlers  saw as mentioned above for 300+ guns ....

I always grin when i see your production number, Mike B.
At my pace of 4 guns a year, I'll hit #300 in 72 more years. 

[Mike Brooks]

I have used the jewlers  saw as mentioned above for 300+ guns ....

I always grin when i see your production number, Mike B.
At my pace of 4 guns a year, I'll hit #300 in 72 more years. 

You'd be surprised how many have built more than I have.

[frogwalking]

I am understanding that when I use my drillpress to drill through the stock and mark the tennon, I remove the barrel, drill two 1/16 inch holes on either side of the mark, cut and file the steel out from between them. 

[Pete G.]

I am understanding that when I use my drillpress to drill through the stock and mark the tennon, I remove the barrel, drill two 1/16 inch holes on either side of the mark, cut and file the steel out from between them. 

You got it. Don't forget to add some space fore and aft on the lug inlets in the stock also.