Installing touch hole liner to raise touch hole.

[James Taylor]

I have a Pedersoli 2nd model short land pattern Brown Bess.
The touch hole was originally drilled too low (right at the bottom of the pan).
I want to raise the touchole.
I've bought a Jim Chambers 3/8" stainless steel "White Lightning" touch hole liner from Track of the Wolf.

Track of the Wolf recommends using an end mill in a milling machine to drill the hole for the touch hole liner- saying a regular drill bit would probably skip into the old hole.

Anyone have an experience with this? Do you have to use a milling machine- can an end mill be used in a drill press?

James Taylor

 

[TANSTAAFL]

Without milling, this is the way I would approach the problem. (for me only :results

Remove old liner, clean the liner threads in barrel thoroughly with solvent, followed by alcohol. I would then take a screw with the correct threads, coat screw threads with "regular" JB Weld (see foot note ) and run it in, let JB Weld cure at room temperature for 24 hours. Cut off protruding portion of the screw and file down smooth to the barrel flat. center punch where I wanted the new liner centered, drill a pilot hole for tap drill, then drill and tap as normal.

(foot note) JB Weld is the best epoxy I have ever found, 500 degrees working temperature, and it is designed to be drilled, tapped or machined.

 

[Donny]

I would do the same..but I would countersink the end of the bolt. ::

 

[BLAHMAN]

Is the pan of the lock thick enough to wallow out the pan? That way, you would lower the pan rather than raise the touchhole.

Just an idea.

 

[LRB]

I don't think the 1/16 vent will affect the drill bit. Drill a pilot hole and then drill it for the Chambers 5/16 liner. Then if you screw up you can still have a machinist bore it for the 3/8

 

[Birddog6]

Unless the tip of the drill bit & the vent hole are in line it most likely will not have a effect on drilling the new hole, being it is a small hole & will be on the cutting edge of the bit rather than the point. I would use a short bit & have everything clamped & etc. Shorter the bit the less deflection it has on the bit shaft from end to tip.

Another easy way to plug it is to just take a finish nail & taper it just a tad & drive it in the hole & file it off flush.

:results:

 

[Darkhorse]

If your Pedersoli has a liner, then taking out the liner and trying to drill it probably WILL cause the drill bit to lead off into the old threaded hole. In which case the best way will be to use an end mill in a milling machine. A regular drill press doesn't work well in this situation as it is not designed to be rigid when horizontal force is applied to the cutter. Even if you are drilling straight down it will still try to follow the old hole. If trying it I would use a 4 flute end mill as short as possible to reduce chatter.
And what about getting an endmill your tap drill size? Are you going to have one specially ground? $$$$$$$$?

When you drill for your new White lightning will the tap hole 100% completely drill out the old threads? If not then you will loose pressure because of gas escaping and it will also erode the threads.
In this case the only option, and probably the best option is to plug the hole like Tansfall suggested. This way you have basically new metal to work with.

On something like this you need to really think ahead and try to cover all the little surprises that might crop up. So if you have to ask a question like this in the first place then maybe you need to consider having a gunsmith do it right from the get go.

 

[Birddog6]

The original post said a vent Hole...... and that was what I am referring to, drilling for a vent Liner.

Now if it already has a vent Liner, then the safest thing to do is as previously stated, plug it with a screw & redrill it plugged. Even then I would do it on a milling machine as there is less chance of it walking & etc. One must be sure you clear ALL of the old threads & get all new full threads. If you use a drill press, use a Short stubby bit & clamp everything securely so nothing can move. If you have a clear shot of solid metal & no threads or hole, I would drill a pilot hole too.
:results:

 

[James Taylor]

Thanks, everyone, for the suggestions.

The Bess in question has only the original vent hole (no vent hole liner).

Track of the Wolf suggests using a .250 end mill (said four flute HSS mill end should work well) in a milling machine- then, using Q drill- and, finally, tapping the hole with the 8/32 tap.

I took the Bess to Bob's Gun Shop here in Norfolk, Virginia, and he said he'd never done anything like this- suggested I find a local machine shop to do it.

I guess I could try filling the existing vent hole with the J B Weld or nail, drilling a small pilot hole, and using a short Q drill bit in a drill press, but I'm a little leery of screwing this up. I'm more of a jack-of-all-trades kind of guy, and the gunsmith not feeling confident that he could do it properly has me very hesitant to do it myself.

Can anyone suggest a good machine shop or a more experienced gunsmith in the Virginia Beach, Norfolk, Portsmouth, Hampton, Newport News, or Williamsburg areas?

Once, again, thanks for the help!

James Taylor

 

An 8/32 tap is considerably smaller than the .250 end mill!!

You said this was a 3/8" liner.

Are we getting confused?

measure everything twice, then sit down for ten minutes and measure it again.

This is one of those "improvements" where you only get one shot!

:front:

 

[James Taylor]

Sorry, typing too fast.
Meant 3/8-32 tap.

James Taylor

 

[B.Habermehl]

I would use Transtaafel's method with one difference, after epoxing a bolt into the old touch hole and filing flush. Center punch. Use a black magic marker and a pair of machinist dividers to lay out a circle just under 5/16 dia and 3/8 around the new touch hole location. Put the whole works back into the stock, install lock and verify the layout. Then set up in the drillpress and I usually pilot drill 5/64 dia. I countersink next to the dia of the liner that I intend to use. The small pilot hole will almost allways prevent countersink chatter. Then drill out to the correct tap drill size. The countersink will act as a funnel and will keep the tap drill from wandering. You will also end up with a countersink that is concentric with the tapped hole this way. When you countersink a tapped hole the countersink will allways wander due to the threads. Use your layout circles to verify your position at each step.
BJH