Drilled Touch hole

I was thinking of drilling out my touch hole to 1/16. I've read on here of other people doing that. So do most people shoot it first to see how it is or just when they buy a new gun they auotmatically drill it out? What does coning do and how do you go about it? Also are there any aftermarket touch holes you can buy? Thanks!

On my Pedersoli Blue Ridge, it would fire regularly, but still had a few flash in the pan. I drilled it out to 1/16th inch and it now fires 99.99999% of the time. As for coning, I took a 1/4 inch bit and counter sunk my vent liner on my GPR. I was having a lot of misfires. I'll try it out next week and see if it helps. You can buy after market vent liners from places like Dixie and Track of the Wolf.

by way of a 'plug,' i have seen a good number of touch hole liners, but none better than the 'white lightnin' which i get from TOW. if you have a drill press, you need only the correct sized drill bit and a countersink tool to get really nice results. if you look on page 401 of catalog #16, you'll see a sort of cross section drawing of one, which will visually explain how they work and why they're worth the extra trouble and expense.

you want the touch hole itself level with the top edge of the pan, and centered on the pan. (the much touted "sunset position") also, remember that a vent liner is slightly bigger on the inside, so don't make the mistake [which i've made] of putting the whole thing too far toward the breech. this will necessitate cutting a v- groove into the face of the breechplug so that the flash from the pan can get to the main charge... humm :: very bad juju... makes it harder to clean the piece, too. use the fine tip felt tip marker to work all this out before you cut the wood, then the trigger will be in the right place, the lock will be where you want it, and you'll have room to put the touch hole liner where it's supposed to go.

good luck!

msw

hey you might go to the gunbuilder thread in this site. There is lots of disscussion on touch holes, size location etc. You might want to use the search feature with words like "touch hole" and see all posts on this topic. Hope this helps.
Good yo see you are yong and getting started in a very rewarding hobby/sport. Hope you stick around!

I start with 1/16 and then go shooting. If you have pan flashes then going up one size may be what you need. I think the next size up will be a #50 drill bit and then a 5/64. Be aware a 5/64 will bring about very reliable ignition but you will have a self priming gun when useing 3F powder. You'll need to plug the vent hole when loading.
There are many different aftermarket liners that are already coned on the inside. Depending on the make of gun you have they may or may not thread right in. I personaly think Chamber's White Lightnin are the best but using one will require you drill and thread the hole.
Hope that helps some.
Ken

Check the big suppliers listed in the links under Member services at the top of the index page here. You should find after market vent liners at Dixie, TOTW, Log Cabin, Cains, and other major suppliers, including Brownells. The Chamber's coned liner works better because the cone is parabolic, like the curve of a inside lens. It helps to focus both heat and pressure in the powder chamber from the gases that are trying to rush back out the vent hole at ignition, delaying that exit, increasing chamber pressure which in turn increases the chamber temperature to ignit the powder faster. A straight sided cone simply directs the venting gases out the small hole, and does not reflect gas, heat, or temperature back into the chamber.

No matter what liner you choose to replace what you have, you are going to have to find out what thread pitch is being used, and then acquire the proper sized drill and tap to prepare the barrel for the liner. There is then further work done with either file, or machines, to reduce the length of the cone on both the inside and outside of your barrel to make a correct fit.

As to the size of the vent, much has to do with the location of the vent in relation to the flashpan, and whether you are using FFFg or FFg powder in your barrel. I first opened my vent to 1/16" but found it still was misfiring on me-- the dreaded " flash in the pan". I then opened my vent up to 5/64" and that cured my hangfires and misfires with that particular lock. However, as already noted, if I decided to use FFFg powder in that gun, I would prbably start with a new vent and keep it at 1/16, unless I still got flashes in the pan. Only then would I open it up to 5/64" knowing that FFFg powder is small enough in size to permit granules of powder to pour out the vent into the pan when loading. I settle on FFg powder in that rifle long before I opened the vent to 5/64".

The important thing about all this is to make the decisions about your particular gun in the right order and at the right time. Find out what powder shoots the most consistently for you and your most accurate load. Then, if you are getting flashes in the pan, consider opening the vent up a little. Don't overdo this, and open the vent only to the next drill size. Try the gun out, and see if that cures the problem. It was only after shooting my gun over 6 months in three seasons that I decided that 1/16" was not going to cure the problems, and I bought a 5/64" drillbit, and open the vent the next step. My particular gun has the vent hole bisected by aline drawn across the top edge of the flashpan, a bit low for best performance. If I could do it over, I would have the vent drilled so that it was slightly above a line drawn over the top of the flashpan. Then, that 1/16" vent hole size might have done the trick for me.

If memory serves you can buy a drill bit between 1/16 and 5/64s. I believe a number 50 is .070, while 1/16 is .0625 and 5/64 is .078.

Using Paul's methodology, I'd try the in-between size first, if the decision was made to go with a larger hole. I don't think that 3fg powder will fall through a #50 bit's hole. I'm not sure.

I like to spin a countersink by hand in the freshly drilled hole to remove the bur and to make a VERY light exterior cone.

Regards,
Pletch

You're right Pelch. There are actually 5 drill sizes {#'s 48 through 52} that are between 1/16 and 5/64".

squirejohn said:

You're right Pletch. There are actually 5 drill sizes {#'s 48 through 52} that are between 1/16 and 5/64".

Click to expand...

Thanks Squire John. I got my chart out:

1/16"---.0625
#52-----.0635
#51-----.0670
#50-----.0700
#49-----.0730
#48-----.0760
5/64"---.0780

If you want to sneak up on that vent hole size, here are the diameters. When I did my article I used only 1/16, #50, and 5/64. I got mine at the local hardware.
Regards,
Pletch

I have a Lyman Great Plains .50 that misfired often. I drilled it out to 5/64" and have not had a problem since. Hope this helps.

Coning the vent liner on my .54 GPR seemed to help a little. Since I already drilled it out with a 1/16th bit, I'm going to drill it woth a 5/64th bit this afternoon. I use FFG Goex, so it shouldn't be a problem. Try it out again this next week. With all the flash in the pan, I know the lock is doing it's part. Just have to get that flash to the main charge :v .

I have a GPR flint .54 and am very pleased with ignition after the following steps:

The liner extended into the powderwell by approx 1&1/2 threads so i shortened it.

The inside i coned as much as possible and ensured a .045 web remained.

The outside was given a very shallow cone.

The hole was opened to .070 (#50 drill).

Big improvement!!

I have probably drilled & coned over a hundred vent liners for dif. people, and the GPR is one I have done allot of. I use a #2 Centerdrill & it drills it out to 5/64" & cones it at the same time. It makes a tremendous dif. in the ignition time on a GPR.

I do the same thing on the slotted Ampco bronze vent liners & it also hakes a big dif.

Everything I have about .40 cal has a 5/64" vent hole. Under .40 cal has a 1/16" vent hole.

When I build a rifle to sell, I drill it to 1/16" and leave it to the customer to decide what size hole he wants there.

:thumbsup:

A lot of good information here from those who have actually done it. I have only just got started shooting flintlock guns. I have shot quite a bunch of cap locks. Flintlocks seem to have a very quick ignition when someone who knows what they are doing is pulling the trigger. Great thread, this one.

Since their introduction I've only used Chambers' "White Lightning" TH liners and drill them out w/ a #51 drill {.067}. This dia allows a pipe cleaner to be used if needed and also eliminates calls from customers......Fred

Packdog said:

I start with 1/16 and then go shooting. If you have pan flashes then going up one size may be what you need. I think the next size up will be a #50 drill bit and then a 5/64. Be aware a 5/64 will bring about very reliable ignition but you will have a self priming gun when useing 3F powder. You'll need to plug the vent hole when loading.
There are many different aftermarket liners that are already coned on the inside. Depending on the make of gun you have they may or may not thread right in. I personaly think Chamber's White Lightnin are the best but using one will require you drill and thread the hole.
Hope that helps some.
Ken

Click to expand...

Lot of good advice from all on this thread. But this comment bothers me:

I start with 1/16 and then go shooting.

Click to expand...

I would advise, go shooting first. Then, if you have an ignition problem consider drilling out the t-hole to a larger size. Once you have drilled, if you go too large, the only way to fix the issue is with a liner. Test first.

How did you remove a GPR touch hole, Mine has no slot.

You have to use an "easy-out"

Here lately I have been paying more attention to the web of the hole. Like "retired" says I like to see almost but not quite a knife edge on the liner. An easy fix is to countersink the outside of the hole until you can see the web you want. Most liners can be cut by twirling a drill bit with your fingers. If you don't like it, the liner can still be replaced. This all started because I have a couple of rifles where I couldn't see the powder at the hole and wondered why.

Hey...good to see Birddog six is still kicking! My Jeager is still the BEST rifle ever, thanks to that man. It is also the most 100% reliable rifle ever, and has the fastest ignition ever. Seriously.