Touch Hole Size

[Jerry]

What is the proper diameter of a touch hole? Thanks, Jerry

[Daryl]

I would suggest .062"  to about .072".
I found the White Lightning liners in the mid .050's to be a little on the small side.
A drilled hole in the side of the barrel is another thing entirely.
The liner must be counter sunk the correct amount so that the "wall" between the inner cone and the outside is about 1/32" thick.
That should give good life and allow you so actually see a powder granule at the vent hole after loading.

[Jerry]

Thanks, Daryl. Good suggestion. The existing hole did look really small. Jerry

[Steeltrap]

So do you drill those white lightning holes a bit bigger?

[David Rase]

So do you drill those white lightning holes a bit bigger?

Yes, .062".
David

[hanshi]

Every vent liner I've used, installed and aftermarket, came with tiny, undersize holes.  Using 1/16" drill bits I drilled all of them out to .062" and got excellent reliability.  Rear sights are usually handled the same way on rifles with the rear blade normally having only a small "guide notch" to assure the user's file remains centered while filing a suitable size notch.

[flatcreek]

I think the powder used in the gun should be considered.  You don't want it spilling into the pan,  That can leave a void at the touch hole, which in turn can cause inconsistent ignition.  If using 3f I use about .055 for 2f about .060.

[Daryl]

To see if you are losing powder out the vent when you seat the ball, try putting the cock at 1/2 bent & closing the frizzen before ramming down the ball.
After the ball is seated, open the frizzen to see how much powder is in the pan.
This is why I suggested .062 to .070" as . 070" is about the max., maybe .072" before replacing the vent.