Touch Hole too high... help!

[Kansas Kid]

Here’s the measurements. Hopefully it will help you.

 

[Kansas Kid]

Treso liners are supposed to be 82 degree CSK. They have screwdriver slot and permanent types.

 

[Zonie]

Umm... Like I mentioned when Eterry said his barrel is a 13/16" octagon, the barrel flats on that barrel are .336 wide.

Unless he wants to see the threads on the liner breaking out into the next higher or lower flat, he would have to center a 5/16" thread within ±.012 of the center of the side flat.

The barrel on his gun is very deep in the stock and IMO, centering the vent liner within ±.012 would bury it too low in the pan.

A liner with a 1/4" thread could be installed with its center within ±.043 of the center of the barrel flat before it starts to break out into the next barrel flat.
A liner made using a #10-32 thread could be installed with its center within ±.073 of the center of the barrel flat before it breaks out.

That .073 offset that could be used might be what's needed to get the vent hole in the right place for the locks pan.

 

[dave_person]

Hi Zonie,
That's why I mentioned that size. It is also because I've mounted white lightning liners on 13/16" barrels although I would never use that size barrel on a gun anymore.

dave

 

[Kansas Kid]

Well he is just in the measurement stage to see what his options are.

 

[Sidney Smith]

Hi Zonie,
That's why I mentioned that size. It is also because I've mounted white lightning liners on 13/16" barrels although I would never use that size barrel on a gun anymore.

dave

Why don't you use a 13/16 barrel anymore? I'd like to know the reasons.

 

[Eterry]

Thanks everyone for the help/ideas/suggestions. I've ordered a Chamber's White Lightning 1/4" vent liner, and hope to get it installed soon.
I'll post updates as they occur.
Et

 

[dave_person]

Why don't you use a 13/16 barrel anymore? I'd like to know the reasons.

Hi Sidney,
First I don't use straight barrels because the balance is terrible. Second, 13/16" is too small in the breech making getting attractive and sturdy architecture in the wrist very difficult. Third, barrels that small are not very useful for 18th century guns. There are some 19th century long rifles with thin barrels but not during the period I am interested in. Mid to late 19th century long rifles, particularly during the percussion era when they were mostly plain or decorated with a lot of ugly metal inlays that were not engraved don't interest me at all.

dave

 

[Sidney Smith]

I understand completely. I did not know when I ordered my 32 cal barrel and ordered mine in 13/ 16. I am realizing that a lot of wood is going to have to come off especially around the lock. I had to go deep just to get the bolster to touch the barrel.

 

[gemmer]

The larger hole may be

All you need to do is install a White Lightnin touch hole liner. The larger hole you will drill for the liner should wipe out your present direct vent touch hole. Make sure you center your drilling where the liner's hole will be in the proper "sunset" position.

Be careful that the larger hole is not too big for the barrel flat.

 

[Eterry]

The larger hole may be


Be careful that the larger hole is not too big for the barrel flat.

The flat is .336", the 1/4" liner is... well ... by definition .250". Not counting the counter sink, that is.

 

[Eterry]

Update...got the WL liner in, took it to a machinist, we did a test run using an end mill cutter to punch thru a piece of 1/4" steel, no wobble. He was satisfied, so he chucked up the barrel, mounted a center drill to mark center, then used the correct cutter to bore thru the barrel. Then he mounted the tap in the collet to keep it concentric and slowly tapped the barrel. Countersunk the hole so the liner fit, then took off a few threads to get the liner short enough.

A hacksaw took off the liner head, then a little file work got it flush. He drilled a small hole in the liner to start...saying i can always go bigger if needed.

I put some anti-seize on the plug and installed it..the hole is right at the base of the plug.

Now I'm browning the barrel where it was filed down, then its back to the range to see whats what.

Film at 11.

 

[Grenadier1758]

Sounds as if you got the mechanical aspects of the installation. You should see marked improvement in firing your rifle.

 

[Col. Batguano]

The trick when installing the liners is to make sure the barrel flat is at a perfect right angle to the drill bit. If it's off a little bit you will get a wee bit of a hair line showing at the edge of the liner. It won't hurt anything to have it, (still safe to shoot) but it won't be perfect. I use a level on the drill table, and again on the flat. With a swamped barrel you need to support and lift up on the muzzle end to make sure the flat is level with the drill press table. (I also assume the table is set at perfect right angles to the chuck spindle.) Then make sure I get a good punch mark, and drill at first with a small bit like 1/16", then 1/8", and so forth. I really hate it when bits walk on me, and this operation is a critical one.

The chamfering bit is a different angle (I think it's 82 degrees) than a normal drill bit. Track sells a specialty chamfering bit just for the WL TH liner.

 

[Sidney Smith]

When I drilled the touch hole in my Smooth bore I just drilled with the final bit the first time. The trick is to definitely get a good center punch mark. The other is to put the spindle of the drill press on a slower speed. My press suggests 3100 rpms for drill bits under 3/16 for steel. I usually go around 1700 or even 1100 . Go slow and don't ram the bit down. Put some cutting oil or even motor oil in the hole and take short bites then back it out to let the chips come out of the hole. Over heated bits dull up quick and combine that with a hole full of metal chips and your assured of a walking bit.

 

[SDSmlf]

Get yourself some center drills from whoever you get your drills from. They do not flex or wander off your center punch mark.