Touch Hole Liner

[Mongo40]

This evening I cut the drum off the CVA Pistol barrel an draw filed it all down then drilled an tapped the hole for this vent liner
Link
Everything going fine except the hole in the liner is about the size of a needle an a small one at that, is it supposed to be drilled out to a certain size or is it supposed to be this small, the one on my flint rifle is a lot bigger, there is no way you could put a toothpick in this one on the pistol to clean it.
Chris

 

[ebiggs1]

I wouldn't want that liner. But it was not intended to be drilled out. That is how they use them. Probably not well but they do. I would drill it with a #50 drill and cone it also.

 

[zimmerstutzen]

One old timer told me that with a inside coned liner, a touch hole opening should be just the same size or slightly smaller than the granulation powder you intend to use. So that when loaded ready to go, you should see powder grains up against the touch hole opening. But not so large as to let the powder fall out into the pan.

I have no scientific reason to like this idea other than it makes sense. There might be 100 reasons why such thinking is wrong.

I have always followed that advice, so on my guns, a rifle 50 and up is set up for 2fg not falling through the touch hole and in lesser calibers, so 3fg won't sift through. For a gun used just for target shooting, and not carrying around, you have little chance that excess powder will sift into the pan, a slightly larger opening may permit a few ten-thousandths of a second faster ignition, Just a theory.

 

[Melton Kidd]

I agree with EBiggs, I don't like that liner. I would drill it to 1/16th, then if the ignition was not to my liking, I would go larger in small increments. I also would inside cone the liner with a tapered bit.

Mel

 

[Mongo40]

The inside of it is coned just the hole is tiny.

 

[Keb]

Mount & file off the screw driver slot flush with the barrel flat. Drill hole out to what the experts say. Give the hole a small lead. It'll work great.

 

[Mongo40]

If I file off the screw driver slot how would I ever remove it??

 

[Keb]

Drill it out.
Clean the threads out.
Install a new one.
File flush again.
Done.

 

[hoochiepapa]

If I file off the screw driver slot how would I ever remove it??

Use an easy-out.

 

[Zonie]

If I file off the screw driver slot how would I ever remove it??

If you want to remove the liner after removing the slot, a sharp center punch can be used to turn it.

Just hold the center punch tip just inside the small diameter of the threads and give it a light tap with a hammer. This will form a small dimple.

Now, holding the center punch at about a 45 degree angle with its point in the dimple, lightly tapping it with a hammer will cause the vent liner to turn.
After getting about two turns made, you can use your fingers to remove the liner.

I've done this several times and if I was careful it worked very well.

 

[ebiggs1]

To each his own but I certainly would not remove the screw driver slot. :bow: