Best vent/touch hole liner?

[M. De Land]

I still don't like the idea of using liners with and interior cone as this will effectively funnel the main charge pressure out ward just as it does the pan flash inward. I don't see how a supposed gain in ignition reliability would off set the probable loss of pressure and thus velocity, let alone lateral vent blast.

 

[8 BORE]

Too technical again.
If it aint broke dont fix it

 

[Zonie]

I still don't like the idea of using liners with and interior cone as this will effectively funnel the main charge pressure out ward just as it does the pan flash inward. I don't see how a supposed gain in ignition reliability would off set the probable loss of pressure and thus velocity, let alone lateral vent blast.

Adding a few more grains of powder will offset the loss of any gas pressure in the breech. This makes regaining the few fps in velocity that is lost thru a short vent liner with an interior cone easy to do. That's one of the benefits of shooting muzzleloaders. It's easy to change the size of the powder load.

 

[M. De Land]

I still don't like the idea of using liners with and interior cone as this will effectively funnel the main charge pressure out ward just as it does the pan flash inward. I don't see how a supposed gain in ignition reliability would off set the probable loss of pressure and thus velocity, let alone lateral vent blast.

The interior cone will also encourage vent erosion. Seems to me that interior liner vent cones are a solution in search of a problem.

 

[Black Hand]

The interior cone will also encourage vent erosion. Seems to me that interior liner vent cones are a solution in search of a problem.

Except for the fact that (some) period barrels were known to have been coned from the inside - saw a neat tool that worked like a 90-degree reamer that was inserted from the breech end to create an interior cone to the touch hole. Interior coning is not a modern idea...

 

[Black Hand]

...and interior cone as this will effectively funnel the main charge pressure out ward just as it does the pan flash inward.

Pressure will take the path of least resistance, which is exploited to push the ball from the barrel. Any pressure loss through the touch hole (whether straight or coned) seems negligible...

 

[WKD]

Why mess around with anything but a white lightning liner? I open mine up with a #49 drill out of habit not necessity.

 

[Grenadier1758]

For the original poster, and anyone who has a touch hole liner installed on the firearm, why mess around with making a change that involves unnecessary machine work for what MAY be no real improvement in ignition.

On a new build, I agree that the White Lightning vent liner is at the top of the list. In the case of the original poster, who already has a 1/4-28 touch hole liner, installing a replacement White Lightning liner means drilling out his existing touch hole to tap a 5/16-32 threaded hole for the new liner. Good 1/4-28 touch hole liners with internal cones are available. Replacement of the existing liner is simple and the cone can be enlarged slightly to have nearly instantaneous ignition of the main charge.

In some cases the 5/16" liner may be too large for the flats for esthetic installation.

All of our responses have called for some variant of an internally coned touch hole. Let's keep the solution as simple as possible. Get an internally coned touch hole liner threaded for 1/4-28. In most cases the touch hole will have to be opened out to 1/16". This is the case for the White Lightning liner.

 

[brayhaven]

All my rifles are white lightening vented as everyone stated super fast, A few questions are you priming with 4 f and how much prime are you placing in the pan, as to flint life the above post gave some great suggestions on different flint positions such as bevel up or down ,placement of the flint in the cock jaws, what are you using in the cock to hold the flint, leather how thick or lead. Possible could not be the vent liner at all.

Dittos on the WL liners. Tried them 20+ years ago and never looked back. I put them in deep enough to wind up @.030-.035 from the main charge. I drill the hole out to .070 and do a very slight 60 deg. chamfer with a tiny carbide countersink, by hand. I prime with Swiss Null-B. Very fast. As for amounts, each gun seems to be different. I have 2 rifles with identical L&R locks, set up the same, but one likes 1 grain and the other likes 3 grains in the pan. I have also replaced 1/4” non WL, liners with the larger WL and on small barrels it can intrude over into the next flat. As long as it’s filed or surface ground (my method) flush with the flat, it looks fine and the ignition improvement quickly makes up for any little annoyance. The nicest rifles are the ones that shoot well.

 

[bldtrailer]

For now I have a 1/4 x28(someday I will drill it out & add a WL, santa please bring me a new drill press) but I just put in a rmc and that will have to do for now . next order for track of w will inclued one of there coned liners.

 

[VJM]

For now I have a 1/4 x28(someday I will drill it out & add a WL, santa please bring me a new drill press) but I just put in a rmc and that will have to do for now . next order for track of w will inclued one of there coned liners.

Has the RMC helped any?

 

[M. De Land]

Except for the fact that (some) period barrels were known to have been coned from the inside - saw a neat tool that worked like a 90-degree reamer that was inserted from the breech end to create an interior cone to the touch hole. Interior coning is not a modern idea...

Yes,I've also seen the tool but physics are physics and there is no way the interior cone does not increase vent back blast to bystanders and erosion to the vent diameter.
Vents and nipples erode from the inside out not the other way around because that is where the greatest heat and pressure comes from.

 

[Black Hand]

Yes,I've also seen the tool but physics are physics and there is no way the interior cone does not increase vent back blast to bystanders and erosion to the vent diameter.

Any evidence to back this up?

 

[M. De Land]

Yes,I've also seen the tool but physics are physics and there is no way the interior cone does not increase vent back blast to bystanders and erosion to the vent diameter.
Vents and nipples erode from the inside out not the other way around because that is where the greatest heat and pressure comes from.

One idea I had , which I'm sure is not original, is to fit the liner to the barrel wall for index then before finishing the out side, remove and mill an arch of groove diameter to the liner interior so that it mates perfectly to the bore wall arch then re-install and finish the exterior. This will preclude any extension or corner to trap fouling in the bore wall.
Clear the vent hole burrs and forget the interior cone.

 

[M. De Land]

Any evidence to back this up?

Yeah, burned out nipple examination on percussion guns and burned out vents on non lined flint guns.

 

[M. De Land]

One idea I had , which I'm sure is not original, is to fit the liner to the barrel wall for index then before finishing the out side, remove and mill an arch of groove diameter to the liner interior so that it mates perfectly to the bore wall arch then re-install and finish the exterior. This will preclude any extension or corner to trap fouling in the bore wall.
Clear the vent hole burrs and forget the interior cone.

As long as I'm running off at the key board I'll share another idea I had to implement the above idea in a more practical way if one is building or rebarreling a gun. The idea is to fit the liner before breeching, then mill or ream out the bore with the liner installed to the groove diameter and sand the tool marks smooth to a point ahead of the liner. This would be a taper cut just as the throat is in a modern gun. Cleaning would be a snap from then on.
This is the notion I will try to implement on the build I'm currently to begin , if practical. I'll take some pictures and post them if it seems like a good idea when I breech the gun.

 

[Black Hand]

Yeah, burned out nipple examination on percussion guns and burned out vents on non lined flint guns.

Subjective assessment at best.

Still doesn't address your claim that "...physics are physics and there is no way the interior cone does not increase vent back blast to bystanders and erosion to the vent diameter."

 

[M. De Land]

As long as I'm running off at the key board I'll share another idea I had to implement the above idea in a more practical way if one is building or rebarreling a gun. The idea is to fit the liner before breeching, then mill or ream out the bore with the liner installed to the groove diameter and sand the tool marks smooth to a point ahead of the liner. This would be a taper cut just as the throat is in a modern gun. Cleaning would be a snap from then on.
This is the notion I will try to implement on the build I'm currently to begin , if practical. I'll take some pictures and post them if it seems like a good idea when I breech the gun.

I'm aware this is risky to lock and pan positioning in relation to the vent which is typically done after breeching but feel it can be worked out before hand with some careful measurements and adherence to the build plan.

 

[M. De Land]

As long as I'm running off at the key board I'll share another idea I had to implement the above idea in a more practical way if one is building or rebarreling a gun. The idea is to fit the liner before breeching, then mill or ream out the bore with the liner installed to the groove diameter and sand the tool marks smooth to a point ahead of the liner. This would be a taper cut just as the throat is in a modern gun. Cleaning would be a snap from then on.
This is the notion I will try to implement on the build I'm currently to begin , if practical. I'll take some pictures and post them if it seems like a good idea when I breech the gun.

In this post I used the term taper cut for the reamed out portion of the bore ahead of the liner. I am talking about the end of the reamed portion only ,the tapering is only from the cylindrical groove diameter to the top of the lands.

 

[M. De Land]

Subjective assessment at best.

Still doesn't address your claim that "...physics are physics and there is no way the interior cone does not increase vent back blast to bystanders and erosion to the vent diameter."

Well it does and there is no way I can say it any plainer. If you happen to have any burned out nipples from percussion guns or a bore scope for a well used vent on a flint gun you can prove it to your self. The erosion will always be from the inside out which means that is where the greater pressure and heat is coming from . A nipple creates a venturi to directional-ize pressure and heat inward for more efficient ignition. The base of a new nipple is flat to make a 90 degree corner to the vent hole. The reason is to cause the most resistance to pressure loss at ignition for a better powder burn. When they burn out the hole will be eroded into a quasi cone shape on the vent interior. Same thing happens in a liner so why would you want to help it out by creating an interior cone to help the pressure to escape.
I would like some one to prove to me that an interior cone has any real benefit advantage to pan ignition because it move the main charge closer to the ignition flame. Far as I can see it is more of a negative than positive. One mans opinion base on his observations.