T o w vent liners

[Shiloh]

My main question is how long should the flash channel be from the bottom of the slot to the inside cone?

Being new to flinters I’m not familiar with some of the terminology. I know what the vent liners are but what about this cone I’m reading about? I bought a blunderbuss from Military Heritage I think it’s called. I had to drill the touch hole so I bought liners from DGW. Now I don’t know if I’ve done it right.

 

[Grenadier1758]

My main question is how long should the flash channel be from the bottom of the slot to the inside cone?

The width of the webbing from the bottom the slot to the inside cone should be 1/16" to 1/8".

 

[Grenadier1758]

Being new to flinters I’m not familiar with some of the terminology. I know what the vent liners are but what about this cone I’m reading about? I bought a blunderbuss from Military Heritage I think it’s called. I had to drill the touch hole so I bought liners from DGW. Now I don’t know if I’ve done it right.

Let's take a look at the various breeches. I have circled in blue the vent liner in the Traditional breech drawing, but all four breeches shown have a vent liner. I have also circled that part of the vent liner that we are calling the cone. It is that internal sharp shaped counter sink that opens up access into the powder chamber. It's simply a cone shaped hole from the touch hole to the end of the vent liner.

 

[flntlokr]

My main question is how long should the flash channel be from the bottom of the slot to the inside cone?

At most (I would say) 1/16". You are creating a venturi which accelerates the flash entering the outer hole, thus squirting it into the powder load with more speed and force IMHO. I make my own liners from 1/4 Dx28 TPI x5/16L ss Allen set screws. I drill a 1/16 hole through the bottom of the socket, and counter sink the inner end of that until the shoulder is minimized to 1/16" or a bit less. I make these and use them in all of mt flinters. I remove them when cleaning to allow me to use a flushing adapter which makes the whole job a lot tidier, Easy removal also allows you to get powder into the chamber around a dry ball, and you can also pry a dry ball forward off the breech plug face to let a bit more powder in. Tou caan even screw in a percussion nipple, and set it off with a hammer to put a hotter spark into a load that doesn't go off with the spark from the flint. I like the Allen screw; I (and many others) messed up too many slots.

 

[hanshi]

With a new liner, whether it comes with the gun or is bought separately, I open the cone with a Dremel & use a cone shaped grinding attachment. And I always drill out the vent hole to 1/16" for sure ignition. I don't remove the liner for routine cleaning and maintenance. It's only when it's removal is "called for" in order to do a particular task.

 

[Pioneer flinter]

Thank you guys for your wealth of knowledge. Now I know what to look for when I deepen the cones on my liners.

 

[SDSmlf]

My main question is how long should the flash channel be from the bottom of the slot to the inside cone?

I like to get it as short as possible, around .010” to .015”. Some would call it almost nothing. I use a #2 center drill with a .078” diameter nose (a little large for many) that I work from the powder side to cut the chamfer. I have been doing this since the 1980s and quite honestly any concerns of a flash in the pan went away when I was shown the technique. I do have a few center drills with the nose ground down to .060”, but just don’t feel I get the performance I want with the smaller size.

I have guns using liners with slots, hex holes, and flush (Chambers White Lightening) and get the same performance from all with the short straight, a chamfer on the powder side and a .078” diameter hole.

Building a gun right now and debating if I want to install a hex liner or a White Lightening purely for the pleasing look.

As far as wearing out the threads by removing the liner, call that an urban legend. You don’t hear about the danger of wearing out all the other threads on guns (and other metal mechanical devices). Wonder why? A properly sized and lubed liner isn’t going to wear out threads in your lifetime.

 

[M. De Land]

It's not so bad as it's not necessary. It's excess wear on the threads. The threads can be cross threaded. The liner is often relatively soft, so the slot wears and may become difficult to remove.

Lots of users remove the liner for cleaning or to provide access to shoot a ball out. If they are satisfied with their experience, then they should continue that practice.

I use vent liners as well but I think the truth of the matter is they are pretty much a 20th century solution in search of a problem as very few originals I have looked at in pictures seem to have had them.

 

[david w]

I use vent liners as well but I think the truth of the matter is they are pretty much a 20th century solution in search of a problem as very few originals I have looked at in pictures seem to have had them.

Vent liners allegedly started in the 1800's near the end of the flintlock era. The softer iron barrels which were straight drilled, had to be parodically redrilled until the hole became so large, it made the barrel unusable. I don't know whom is accredited for liners, but it came from the UK. He was a riight fart smeller!

 

[Shiloh]

Let's take a look at the various breeches. I have circled in blue the vent liner in the Traditional breech drawing, but all four breeches shown have a vent liner. I have also circled that part of the vent liner that we are calling the cone. It is that internal sharp shaped counter sink that opens up access into the powder chamber. It's simply a cone shaped hole from the touch hole to the end of the vent liner.

View attachment 193537

Thank you. That’s kinda what I had in mind but the part I wasn’t sure about was if you didn’t have a removable liner then you wouldn’t have that inner cone.

 

[Grenadier1758]

@Shiloh, a vent liner isn't necessary for an internal cone to be machined in the barrel. Various ingenious tools have been developed to insert a cone cutting tool bit into the touch hole. Some of the tools had right angle drives that turned the cone shaped cutting tool. Other tools had a shaft just long enough to be turned to cut the internal cone. I was able to do something similar when I retrieved my Dremel tool from the secure lock box to grind a small internal cone for my 1803 Harper's Ferry rifle. That rifle has very fast ignition.

 

[Shiloh]

@Shiloh, a vent liner isn't necessary for an internal cone to be machined in the barrel. Various ingenious tools have been developed to insert a cone cutting tool bit into the touch hole. Some of the tools had right angle drives that turned the cone shaped cutting tool. Other tools had a shaft just long enough to be turned to cut the internal cone. I was able to do something similar when I retrieved my Dremel tool from the secure lock box to grind a small internal cone for my 1803 Harper's Ferry rifle. That rifle has very fast ignition.

I worked as a machinist for several years and at times I thought a tool like that would be handy for deburring inside holes. I never knew such a tool even existed.

 

[M. De Land]

At most (I would say) 1/16". You are creating a venturi which accelerates the flash entering the outer hole, thus squirting it into the powder load with more speed and force IMHO. I make my own liners from 1/4 Dx28 TPI x5/16L ss Allen set screws. I drill a 1/16 hole through the bottom of the socket, and counter sink the inner end of that until the shoulder is minimized to 1/16" or a bit less. I make these and use them in all of mt flinters. I remove them when cleaning to allow me to use a flushing adapter which makes the whole job a lot tidier, Easy removal also allows you to get powder into the chamber around a dry ball, and you can also pry a dry ball forward off the breech plug face to let a bit more powder in. Tou caan even screw in a percussion nipple, and set it off with a hammer to put a hotter spark into a load that doesn't go off with the spark from the flint. I like the Allen screw; I (and many others) messed up too many slots.

 

[M. De Land]

I feel if one removes nipples for cleaning then why not remove liners if they have a slot or Allen head ? If they don't have a means to easily remove then they were designed that way and should be left alone.
The problem with most liners is that they do not have a sealing ledge all the way around the interior face to seal breech pressure as does a breech plug or nipple and as a consequence tend to allow fouling to penetrate the threads over time.
I prefer the outer face cone instead of the interior cone in the liners I make as I hate the increased outward blast that interior coned liners make by vectoring the interior pressure outwards. If you have ever been burned by a White Lighting liner flash from a fellow shooter in the next lane over, you get the point !
Seems to me the right approach is to vector the pan flash inwards instead and it looks like it works in the one I made for my SMR.
One other idea I have not yet tried is to make liners to be removed with a tiny spanner wrench instead of Allen head or slot so as not to disturb the pan flash flow as much.

 

[Mad L]

Why is it bad to remove the vent liner for cleaning?

Because:
1) People don't know how to use a screwdriver.
2) People don't use proper screwdrivers.
3) People don't know how to start threads without cross threading.
4) People over tighten.
5) People don't grease the threads.

Me: I remove liners and nipples Every time I clean. Never had a problem.