Help with touch hole

[jjsharpshooter]

I recently purchased a used custom longrifle (my first custom) and have a question about the touch hole liner. The liner threads aren't drilled the whole way into the bbl, they stop short with just a flash hole going in. The liner bottoms out in the hole and is filed flush with the bbl. When dropping a ramrod into the bbl, the rear edge of the flash hole seems to be at the edge of the breechplug (the hole is not in the plug). Is this a quality installation? Should it be like this? The thread is 1/4"-28, can I drill this through and install a white lightning liner? I haven't shot the gun yet but worry the flash has to travel a far way to reach the main charge. I'm new to these custom builds and have learned a lot reading the forum here, thanks for all the help, John.

[Dennis Glazener]

Looks to me that the builder intended to only shorten the actual travel time through the vent to the powder column by having a large chamber between the pan and the powder (similiar to a reverse conning of the vent). I have heard some believed this help's ignition. I would not want it if for no other reason than looks.

Whether you can change to a white lightning depends on whether the existing hole/threads will clean up so you can install a 3/8 liner which is the largest Jim makes.
Dennis

[ddoyle]

Luckily you cannot see it with the pan down.
I'd be tempted to put that barrel in a vise and twist the plug out.

[T*O*F]

I'd leave it alone until such time as the hole in the liner becomes too large.  There is nothing wrong with the design, regardless of what the "experts" say.  It's done that way so the existing liner will have a base to tighten up against.  Otherwise nothing would keep it from floating in the hole unless it were rusted or locktited in.  It also keeps the liner from protruding into the breech area and snagging patches or creating a powder trap.

It has obviously worked fine before you acquired it.  Why create extra work for the sake of prejudicial opinions?

[flehto]

I agree ...but, my only objection is that the hex is on the outside. I've made this setup and it worked fine, but the hex on the inside works better and doesn't look "funny". To unscrew the liner, I filed 2 angled slots at 45 degrees on the outside dia and made a "spanner wrench" to unscrew the liner. Don't like a screwdriver slot across the TH. Keep as is, but if you find the hex objectionable, get a new set screw and put the hex on the inside.....Fred

[Robby]

Looks to me that the hole into the barrel bore is very small and would negate the purpose of having a liner. I would enlarge that hole as much as I could, insuring the powder can get to the inside of the liner, and still keep a shoulder for the liner to butt against. I'm assuming the allen head bottoms out with a smaller hole that leads to an expanded area inside the threads of the liner.
Robby

[jjsharpshooter]

Thanks for the replys, I plan on keeping it as is and see how the ignition is first.

[Dennis Glazener]

I'd leave it alone until such time as the hole in the liner becomes too large.  There is nothing wrong with the design, regardless of what the "experts" say.  It's done that way so the existing liner will have a base to tighten up against.  Otherwise nothing would keep it from floating in the hole unless it were rusted or locktited in.  It also keeps the liner from protruding into the breech area and snagging patches or creating a powder trap.

It has obviously worked fine before you acquired it.  Why create extra work for the sake of prejudicial opinions?

TOF
If you would read my and DDoyle's replies without "prejudicial opinion" you will note that neither of us said anything about the design or how well it works. My comment about not wanting one like it refers to looks. I have never owned or shot a rifle with this type vent liner and can not comment on how well it works! I don't give advice about something I don't have first hand experience with.
Dennis

[T*O*F]

If you would read my and DDoyle's replies without "prejudicial opinion" you will note that neither of us said anything about the design or how well it works. My comment about not wanting one like it refers to looks.

Dennis,
Obviously you read something into my reply with "prejudicial inference."  Nothing I wrote referred to any of the replies and expressed only my opinion.  If I happen to disagree with anyone, I tend to call them out in person and debate them directly about whatever it is we disagree about.

[Ted Kramer]

John,

As far as the design being safe, no worry there. You have plenty of threads holding the liner in place, as long as the threads are a good fit with the threads on the liner.

However, the design may cause slow firing since the pan powder may settle into the allen head channel and act like a fuse to the main charge. But, try it and see, it may work just fine.

If not, you could easily install a regular 1/4x28 liner. I'd make sure the hole into the bore (past the threads) will allow a #21 drill bit (.159")  or at least a 5/32" bit (.1562") to pass through, being very careful not to damage the threads. Either size bit is about the size of the cone diameter on a 1/4x28 liner. This will allow the powder from the main charge to enter the liner and still leave the shoulder for the liner to butt up to. Then fit the new liner.

Good luck with it .

Ted K

[OldSchool]

quote: "the pan powder may settle into the allen head channel and act like a fuse to the main charge"
Ted, is there anything other than anecdotal evidence that a 1/4 inch black powder fuse burns slowly?
I would think that it would have to be measured in micro seconds.
Just asking.
Pual

[frogwalking]

About the burn rate of a 1/4 inch, enclosed "fuse":  [/b]...As a teenager, my mother had a sheep die, and offered to pay me $5.00 to bury it.  My buddy, Russell was there, and we decided to make a black powder bomb (powder was $1.25 a pound), blow the hole, bury the sheep and net $3.75 in short order.  We dug a deep hole with post hole diggers.  Put the powder in a plastic bottle, but had no fuse.  My dad had a bunch of 1.4 inch clear plastic tubing.  We took 4 ft. of tubing, filled it with powder, put the fuse in the bottle and tamped the hole full of dirt.  Russell cried "I want to light it.  You always get to light the fuse."  I handed him the box of kitchen matches without a word.  He lit the "fuse".  About 1/2 second later the bomb went off.  Russell was standing with one foot in the hole, and his entire right side was covered with mud and dirt and smoking.  His hand was still outstretched with the remains of the match in it,  (Russell is now retired, and still can hardly hear out of his right ear.) Witnessing the aftermath of this, my sister asked why we didn't just blow up the sheep?  Thank God we did not think of that.  The moral of this?  A 1/4 inch confined black powder "fuse" burns really fast.

[sqrldog]

These touch holes are frequently found on Jack Garner rifles. I gave one to my grandson to shoot and it seems to be about as  quick as any I own including touch holes coned from the inside the barrel with no liner, white lightning touch holes and the other styles of liners. Aesthetically is may be offense, but in all probability will function just fine. Ted Kramer's suggestion is spot on if you want to change the liner, otherwise you may need to pull the breech plug to install a new liner. Then there arises the theory that early rifles were built without liners. They had simple drilled holes. Wonder how fast they were? Tim

[Ky-Flinter]

When I built my first flintlock, I made a liner out of an allen set screw like yours, but I used a dremel to "cone" the inside face of the liner.  The cross-section of the liner was like an hourglass.  It was quick to fire.

-Ron

[Bob Roller]

These touch holes are frequently found on Jack Garner rifles. I gave one to my grandson to shoot and it seems to be about as  quick as any I own including touch holes coned from the inside the barrel with no liner, white lightning touch holes and the other styles of liners. Aesthetically is may be offense, but in all probability will function just fine. Ted Kramer's suggestion is spot on if you want to change the liner, otherwise you may need to pull the breech plug to install a new liner. Then there arises the theory that early rifles were built without liners. They had simple drilled holes. Wonder how fast they were? Tim

The old style flintlock rifles that had a only a small hole in the barrel gave rise to holding through the ignition cycle. That had to be a common practice in "the day"when that's all there was.The Brits gave us the lightning fast locks and the vents to go with them along with all kinds of Patented improvements. I saw a cartoon spoofing this patent mania that showed a gun going off and killing everything around it.
Bob Roller

[Ted Kramer]

quote: "the pan powder may settle into the allen head channel and act like a fuse to the main charge"
Ted, is there anything other than anecdotal evidence that a 1/4 inch black powder fuse burns slowly?
I would think that it would have to be measured in micro seconds.
Just asking.
Pual

OldSchool- No evidence other than my own experience. And no, I didn't measure the difference with a timer. As I said in my other post, it may work just fine for John's rifle and I hope it does.
Ted K.

[moleeyes36]

I've had guns in the past that came with this type of vent and I usually changed them out with White Lightning vents.  That's just my personal preference.  I suspect that if you could find some tests measuring the time required to ignite the main charge using this type of vent versus other types of vents you might find some small difference.  However, they would have to be accurate tests of the quality that Pletch conducts or the results would be primarily subjective.

The main problem I've experienced with the type of vent pictured in the original post is fouling in that sunken hex shaped cavity.  Even though you pick the vent after each shot, fouling builds up on the walls and effectively reduces the size of the cavity.  Granted, I shoot in the high humidity of the Southeast where fouling is more of a problem.  I found that for me to get reliable and quick ignition of the main charge I needed to clean the hex cavity with the end of a pipe cleaner every few shots in addition to the usual picking of the vent.  If I did that, things worked just spiffy.  These are my experiences, yours may vary.

Mole Eyes

[bob in the woods]

Mole Eyes , your experience duplicates mine. I had a .36 cal rifle with that type of liner [ many many years ago]
and it was a frustrating fouling trap.

[Daryl]

Ditto, Bob.

[jjsharpshooter]

Thanks everyone, lots or good points and ideas to ponder.

[JCurtiss]

At the risk of belaboring the subject, the book Recreating The American Longrifle by Wm. Buchele and G. Shumway suggest that a socket head cap screw is an effective vent liner.

[bgf]

These are coned on the inside:
https://www.trackofthewolf.com/Categories/PartDetail.aspx/960/1/THL-S4S
I'm sure white lightning is tiny bit faster, but these work fine when installed correctly and use standard drill and tap sizes.

They make another style with a lug you cut off that looks better, but I replace vent liners about every year or two on the two rifles I use the most, and the screw slot is handy, also if you dryball, though no one ever does ...