Touch hole liners??????????

[jwh1947]

I know I am going to stir the pot on this one.  I am unrepentant; so be it.  Go ahead and fire away.  I'm in the bunker.

I am an avocational builder of hunting rifles.  I have only applied one touch-hole liner at the demand of a client; the other 26 that I have done were simply drilled with a #50 drill bit. 

I have often wondered why so many contemporary builders use liners.  Look at the originals and take a percentage.  This dumb Dutchman has always seen it as another seam at a most critical area adjacent to the explosion.  I always figured that such a liner would be useful as a retrofit for a burned out touch hole, otherwise, a contemporary do-dad, more unfit than fit for a traditional rifle.

I have heard all kinds of stories of faster ignition, but, I think that this is essentially so miniscule in value as to be complete bunk in operational terms.  I am suspicious of those who tell me that they can discern a difference.

Well, I feel vindicated.  At our first meeting of the latest course at Jacobsburg, taught there by three of the nation's premier traditional working gunsmiths, I raised the question.

Here's what I was told and what I saw.  All three Pennsylvania gunsmiths, comprising some 125 years of experience together, claimed that liners were entirely superfluous, and the result of nothing more than customer demand.  Builders put them in because of customers expect them, not because they serve any significant purpose.  Included in this gunsmithing experience are many prizes and records at Shartlesville, the oldest black-powder Mecca in the country.  No liners were used by these participants. 

Moreover, the teachers had "living proof" of touch-hole liner "issues."  If you are planning to apply a touch hole liner to a big bore with a thin wall, you'd better think again.  Yesterday I saw one completely blown out.  I also saw a cut-away barrel showing a touch hole liner job where the liner protruded into the barrel by, say, 1/64".  The rod and cleaner stopped on the liner and the subsequent corrosion ate through and compromised the breech.  Not all hunky-dory, at best.

I have never had a gun returned for a liner and do not intend to start promoting them.   Wayne

[rich pierce]

I don't have that much experience with and w/o touch hole liners, because i have built most guns on spec and customers do want them.  I was pleasantly surprised to have consistent ignition on my last build which has a simple drilled vent.  "N" of 1; meaningless.  Larry Pletcher has done the timing studies.  I think it depends somewhat on barrel wall thickness, but there were many original Southern mountain rifles with thick barrels of small caliber with simple drilled vents.  It can be done.  I think PERHAPS the sport is moving away from target shooting which was a big focus up through the 80's at least, to more re-enacting, where perhaps customers will prefer a straight drilled vent.  But in the 1970's and since, all books telling how to build longrifles told us that internally coned vent liners would give faster and more consistent ignition.  So they became standard, as you pointed out, in contrast to what was found on originals.

[smylee grouch]

This would be a great before and after experiment, if we could get accurate timeing of the ignition sequence. Every thing except drilled hole and vent liner the same . Better yet if we could do it with different size/cal. barrels. Maybe throw in some cronograph data on each variation too. Any science lab people among us?    Gary

[Dphariss]

I know I am going to stir the pot on this one.  I am unrepentant; so be it.  Go ahead and fire away.  I'm in the bunker.

I am an avocational builder of hunting rifles.  I have only applied one touch-hole liner at the demand of a client; the other 26 that I have done were simply drilled with a #50 drill bit. 

I have often wondered why so many contemporary builders use liners.  Look at the originals and take a percentage.  This dumb Dutchman has always seen it as another seam at a most critical area adjacent to the explosion.  I always figured that such a liner would be useful as a retrofit for a burned out touch hole, otherwise, a contemporary do-dad, more unfit than fit for a traditional rifle.

I have heard all kinds of stories of faster ignition, but, I think that this is essentially so miniscule in value as to be complete bunk in operational terms.  I am suspicious of those who tell me that they can discern a difference.

Well, I feel vindicated.  At our first meeting of the latest course at Jacobsburg, taught there by three of the nation's premier traditional working gunsmiths, I raised the question.

Here's what I was told and what I saw.  All three Pennsylvania gunsmiths, comprising some 125 years of experience together, claimed that liners were entirely superfluous, and the result of nothing more than customer demand.  Builders put them in because of customers expect them, not because they serve any significant purpose.  Included in this gunsmithing experience are many prizes and records at Shartlesville, the oldest black-powder Mecca in the country.  No liners were used by these participants. 

Moreover, the teachers had "living proof" of touch-hole liner "issues."  If you are planning to apply a touch hole liner to a big bore with a thin wall, you'd better think again.  Yesterday I saw one completely blown out.  I also saw a cut-away barrel showing a touch hole liner job where the liner protruded into the barrel by, say, 1/64".  The rod and cleaner stopped on the liner and the subsequent corrosion ate through and compromised the breech.  Not all hunky-dory, at best.

I have never had a gun returned for a liner and do not intend to start promoting them.   Wayne

I completely abandoned plain vents in the 1970s.
In my experience and that of a maker who has made in excess of 500 rifles starting circa 1949, mostly flint, the lack of a liner results in a significant reduction in reliability. Having made them both ways I use liners, usually shop made since I can better control thread clearances.
I do not like large diameter liners (over 1/4")  but properly installed you cannot blow one out nor will they interfere with cleaning. If some fool improperly installed a breech and it blew out would it be the fault of the breech or of the fool who installed it?
Also a poorly designed liner can be a serious problem.
A friend has an original heavy barreled flint bench rifle. Plain vent. Shoots pretty good but due to the heavy barrel is pretty slow. He is a 40 year flintlock shooter and knows a liner would fix it but a liner is out of the question as is shooting it enough to further erode the vent.
If you have never used a vent liner then this is really a pointless discussion since we have no common frame of reference.
You indicate you have never used one to any extent but cannot tell the difference anyway. How would you know?
Also actual tests prove that vents larger than .062 degrade accuracy.

Dan

[Larry Pletcher]

This would be a great before and after experiment, if we could get accurate timeing of the ignition sequence. Every thing except drilled hole and vent liner the same . Better yet if we could do it with different size/cal. barrels. Maybe throw in some chronograph data on each variation too. Any science lab people among us?    Gary

Funny you should ask that question, Gary.  The data has already been collected and reported on.  I timed straight cylinder holes for a MB article earlier, and vent liners were a part of a larger experiment dealing with vent placement and powder location in the pan.  Data from those tests can be compared.   I'll get back with some numbers.
Regards,
Pletch

[roundball]

Included in this gunsmithing experience are many prizes and records at Shartlesville, the oldest black-powder Mecca in the country.  No liners were used by these participants.  

Well...if "no liners were used by these participants", then that has no bearing on who won prizes...because SOMEBODY had to win prizes
 

I will say I've never shot a Flintlock without a liner...but I will also say that my Flintlocks with big coned liners are amazingly fast and seem to lack for nothing.
Since I'm not a dyed in the wool purist I'm fine with vent liners...and speaking just for myself, it doesn't make a lot of sense for me to draw the line there when I'm sitting on a deer stand wearing modern Thinsulate, Gore-Tex, and Fleece in my hunting clothes and boots.
 

[Captchee]

 I would agree with Dphariss  on the subject  to some existent
 I have built many rifles through the years , with and without liners .
 Concerning those without liners . I have done  both  strait drilled  as well as  the method of coning the inside of the bore . Which in reality  produces a flash channel  somewhat like  what a liner provides . But with a  much thicker wall  between the pan and the main charge .
Personally   I feel the liner provides faster more consistent ignition   then coning /cherrying the inside of a strait drill . And much more then  just a standard strait drill .
 But again this depends on the size of the flash hole itself . To often though folks say :  I don’t have a liner and my ignition is fast and consistent. But when you look at their flash hole  , its much bigger then  the hole on a liner . So really  any testing on speed would IMO also have to include  same size holes  or the comparison would be apples and oranges .
 Defiantly though the bigger the flash hole  .the  more pressure that is vented . Thus producing less bore pressure and a lower MV

 I also believe it effecst the speed of the ignition . However  not so much that  a person who does not shoot a lot , would ever really know   until they  tried a rifle with a liner . .

I also agree that a liner properly  set , is no more likely to come out then  would a drum bolster ,  or its clean out screw ..
 Now if we are talking  documentation . Then , the liner shouldn’t be there .
 Well , I guess depending on the rifle  one is making . .
 So in that aspect I would agree with the original poster here ..

Anyway . That’s my 2 cents .  For  right or wrong

[T*O*F]

http://home.comcast.net/~illinewek/faqs/conedhole.htm

[pathfinder]

I feel a little funny responding to this issue due to the lack of experience as compared to others here,but I've been building for a little while and do know just enough to make me dangerous! I like liners if installed correctly and "feel" they do make a difference in ignition,can I prove it? No. Do I "feel" better using one? Yes.
The tool shown is pretty cool,but how commonly was it used? Not trying to be difficult,but trying to learn, How often was the inside of the vent hole countersunk, and when did liners become common. Is it like the use of short starters than many say became common in the '60's/'70's?

[Pete G.]

I built a pistol with a 45 cal x 13/16 barrel with a straight drilled vent of 5/64". Ignition was ok, but reliability suffered unless the vent was picked every time. I installed a Jim Chambers WL liner drilled to 1/16". Difference was daylight and dark. Accuracy improved dramatically due to better "shootability" (if that's a word). Perhaps a larger caliber which would leave a shorter vent would be different. Maybe a rifle would be different, who knows, but in my sample of 1 a liner made a big difference.

What I did learn for certain is that you will not go wrong listening to Jim Chambers.

[Acer Saccharum]

I just built a gun, and did not install a liner. Touch hole diameter is .078. Ignition is like waiting for the bus. The barrel is 1 1/4 at the breech, .62 cal., which leaves approximately 5/16 wall thickness.

I am installing a liner. I bought some 4140 steel liners from Jim Chambers, so they will rust up with the rest of the barrel, be right near invisible.

I'd love to make one of those eggbeater tools, but that is for 'one of those days' kinds of projects.

[Jim Kibler]

Tom,

Tom Snyder makes great little tool for internally coning a touchole.  Think there may have been a discussion about it previously.  Basically it's just a 1/16" shank that threads into a cutter inserted through the breech of the barrel.  You spin it with a drill while pulling out.  Simple and works really slick.  I had been using the steel liners, but I like this better.

Jim

[Acer Saccharum]

Jim, you mean I can BUY this, I don't have to make it? More info please?

[Jim Kibler]

Yeah Tom,  Just get hold of Tom Snyder (posts under "Snyder" here) and I'm sure he'll fix you up.

[James Rogers]

Tom,

Tom Snyder makes great little tool for internally coning a touchole.  Think there may have been a discussion about it previously.  Basically it's just a 1/16" shank that threads into a cutter inserted through the breech of the barrel.  You spin it with a drill while pulling out.  Simple and works really slick.  I had been using the steel liners, but I like this better.

Jim

No more liners for me either. I use Toms cutter tool as well with much success when the cock comes down.

[rdillon]

Hmmm.  Wish I would have known that before. I just installed one of Jim's 4140 steel liners to be "politically correct" and have fast ignition at the same time in the gun I'm donating for the CLA Auction.

Oh well, I will contact Snyder and give it a try on the next one.

Rich

[Larry Pletcher]

I tried to put together the numerical information to compare straight cylinder vent holes to vent liners.  But first, I will try to limit my thoughts to numbers only.

In the Feb. 2000 issue of MuzzleBlasts I published an article called “Touch Hole Ignition Timing.”  I timed what I thought was “too small” to “too big.”  This first hole diameter was .040”.  It was plainly too small and the test was terminated without finishing all 20 trials.  Every additional hole size was timed 20 trials and the average determined.  Below is a summary of the test results:

Diameter----------average----------------variation
.052------------------.0523-------------------.0671
.055------------------.0474-------------------.0359
.0625 (1/16)----------.044-------------------.0321
.0625 (ex.coned)------.0406------------------.0278
.070-------------------.0408------------------.0389
.078 (5/64)------------.0445-----------------.0322
.086-------------------.0418------------------.0326
.094 (3/32)------------.0436------------------.0242

In March 2009 issue of MuzzleBlasts I published an article dealing with priming powder location in the pan.  This article can be seen at the following link:
http://www.blackpowdermag.com/featured-articles/pan-vent-experiments.php
(The article has 6 parts.  The link takes you to the intro.  Parts 5&6 get to the meat of the data.)  Here you can see the equipment used in both articles.

The same equipment was used as in the earlier testing except that a Chambers liner drilled to .064 was used.  This hole size was used for 2 reasons.  First, it places the size in the same range as the best performing straight cylinder holes.  Second it allowed the use of a pipe cleaner between shots.

Since the article purpose was to determine where the prime should be placed, it will be that data that we will look at.  In three different tests, placing the powder as close as possible to the vent was fastest.  (This was true even if the prime covered the vent.  The closer you stand to the bonfire the hotter it is.)  These tests also looked at the vertical location of the vent in relation to the pan.  Below are the 3 vent locations with averages for the close position of the prime.

Vent location------------------average-----------------------variation
Level vent (close prime)--------.036------------------------------.025
Low vent  (close prime)---------.034------------------------------.024
High vent (close prime)---------.038------------------------------.015

To sum up, are liners faster? Yes.  Can the difference be measured? Yes.  Can you hear the difference? Probably not --- unless the barrel is very large with very thick walls.  In our testing with a thinner barrel, we could hear NO difference.

If you have a strong opinion about vent liners, you probably have already drawn your conclusions.  The slightly increased speed may justify installing them.  You may also see the slightly increased speed as not enough to justify its installation.   I believe it depends on what the gun is meant to do.  In a heavy barrel competition gun, it would be a good idea IMHO.  In a slim barrel the liner may not add as much.  I’ll let you fight this past out.
It should be pointed out here that mis-management of the lock makes a bigger difference than liner vs no liner.  I can take a vent liner gun, bank the prime away from the vent, and make it slower than a straight cylinder hole. 

In case you ever want to “slow down” your flint lock here are a few hints:
1.   Drill a straight cylinder vent hole with a No. 55 bit (.052)
2.   Locate the vent 1/16 higher that the surface of the pan.
3.   Bank the prime away from the vent
4.   Use a large granule powder ffg or larger.
5.   Don’t worry about fouling – a little dirt never hurt anything.
(These are from a number of tests, some not included here.)

If I wanted to get the most out of a straight cylinder hole:
   Drill the vent a little below the pan surface – lower is faster than higher.
   Use a #51 (.067) or #52 (.064) bit (allows a pipe cleaner)
   Lightly cone the exterior with a countersink.
   Use Swiss Null b for prime.
   Place the prime as close as possible to the vent.
   Use a pipe cleaner between shots.
(These steps should get the most from your vent liner gun as well.) 
OK. This is long enough.  I hope I got down the important parts.  I need to think about an experiment coming up.   Steve Chapman and I are going to time some “Flash” priming powder on Wed.

Regards,
Pletch

[jwh1947]

I will place my bets on an experienced Pennsylvania woodsman who can hold steady, near flinchless---tiny wobble area, through the process rendered by a #50 hole over any less experienced shooter with the "faster" liner.  I'm really having fun here, and learning.  Guys, I don't doubt a minute speed increase, but I doubt its statistical significance counted in white tail deer kills and shooting prizes. 

OK, physics majors: isn't it the heat, not the flame that ignites the main charge?  Show me some numbers on that chronograph.  Afterwards, take the lined rifle and a straight, traditional drilled rifle, have 10 accomplished riflemen test the rifles, in a blind sitiuation, compare results of the two rifles, then come talk to me and we can discuss  mean and variance of results.

Now, this is only crudely spelled out, but the basis of an experiment that would possibly answer the question.  All I reported was my disregard for them and 125 years of traditional building by men who know more than I do.  Wayne

[Roger Fisher]

Larry : Thanks a ton, for all your work and time in your testing and I'm sure all the shooters that read your test results will also thank you!

[Larry Pletcher]

Roger,  Thank you for your thoughts.

Wayne,
We agree on a number of things.  I'll take the expert marksman with a cylinder hole too.  Skill, like cream, comes to the top. But take that expert marksman and give him the faster setup, and I bet he comes back for more.  Statistically I can't say if it puts more venison on the table. 

As to the heat vs flame argument, I don't know.  I'd speculate that the more fire you have,  the more heat you get. 

Let me throw out an idea that may be related.  We have always thought of the pan charge and barrel charge was two items.  In a cylinder hole I think this is true.  But how close do the two charges have to be before we consider tham one charge?  When the barrel charge is .025" away from the pan charge, maybe we should think of them as a single charge.

If you looked at the link to the experiment you noticed that I took small steps, and limited variables.  (We were insane with our cleaning to eliminate fouling as a variable.)  Your idea of using 10 expert shooters is an interesting idea, but brings with it a multitude of variables that would have to be controlled.  As an experimentor I would expect 6 months and a 100% pay raise to set up the trials.  Oh, wait a minute.  100% raise on a 0 salary is still 0.  I guess at my pay rate you'll have to be satisfied with simple experiments and one variable at a time. 

As far as liner or no, I figure each shooter has to dcide that.  (I think Tom Snyder's solution is cool.)  I do think most of us want the best we can afford.  I pay extra for a top quality lock and the best barrel I can find.  Do I have a Chambers liner in my rifle?  Sure.  Headed back to the bunker now.
Regards,
Pletch   

[Ky-Flinter]

Pletch,
I second Roger's thanks to you!  I hope you continue to enjoy the work that we all benefit from.  Amen to the 100% pay raise for you!

My first rifle was originally a caplock, then converted to flint.  I made a liner out of a 1/4-28 set screw, recessed hex on the outside and I "coned" the inside with a Dremel.  I was thinking "hourglass", real PC, but fast.  

Second rifle, Chambers WL.  I like it.

-Ron

[smylee grouch]

Thanks Larry, I thought we might hear from you when I asked for science types and you did not disapoint. This is a very interesting topic and I think we all should thank you for your efforts, regardless of which side of the fence each of us sits. I too have made and shot both drilled and vented and I prefere vented.  I think some of the old guns had liners instaled after they were shot out. Has any one ever taken one of those liners out to see if they were coned? Again thanks Larry and every one for an interesting discussion so far.   Gary

[Licensed to kill]

Jim, you mean I can BUY this, I don't have to make it? More info please?

You can BUY muzzleloading guns also, you don't have to make them. Need more info?

[Licensed to kill]

Many (most?) of the flintlock ignition improvements were born in London by some of the worlds best makers. Liners were common, in one form or another, in London's best guns particularily fowling pieces where ignition speed and consistency is far more important than a rifle shooing at a stationary target. While the advantages of a liner were significant in the type of shooting done in England, they were likley just not worth the effort for what is gained in the type of shooting done in America. Just because the makers in Penna didn't use them by NO means suggests that they don't improve ignition.

[Dphariss]

I will place my bets on an experienced Pennsylvania woodsman who can hold steady, near flinchless---tiny wobble area, through the process rendered by a #50 hole over any less experienced shooter with the "faster" liner.  I'm really having fun here, and learning.  Guys, I don't doubt a minute speed increase, but I doubt its statistical significance counted in white tail deer kills and shooting prizes. 

OK, physics majors: isn't it the heat, not the flame that ignites the main charge?  Show me some numbers on that chronograph.  Afterwards, take the lined rifle and a straight, traditional drilled rifle, have 10 accomplished riflemen test the rifles, in a blind sitiuation, compare results of the two rifles, then come talk to me and we can discuss  mean and variance of results.

Now, this is only crudely spelled out, but the basis of an experiment that would possibly answer the question.  All I reported was my disregard for them and 125 years of traditional building by men who know more than I do.  Wayne

Speed is not the only consideration. In actual shooting velocity variation and powder blown out of the vent when loading or possibly even after ignition are also factors in how the rifle shoots as opposed to how it tests.
Lock time is important. The spread on the various vents and liners Larry tested is bigger than the total time of some modern guns even the modern BR shooters like faster times since the groups are smaller.
Take one rifle (or even just a barrel and lock) put it in a machine rest and then do load development and see which will shoot smaller by changing vents. We are testing the gun not the shooter. Of course it might take a case of powder to find the best loads for all the various vents so is suppose it would be best to start with a 1" breech 50 and use a #50 plain, .078 plain and 3/32" plain. Then try a couple of liners with 3-4 vent sizes each.
A chronograph could be used to check velocity loss as the vents are enlarged. A .0937 (3/32) vent will flow more than double the gas of a .062" (1/16) vent.  Area of a .0625 vent is .0030", the area of a .0937 vent is .00689".
As I said there are other things besides just speed.

Dan