Touch Hole Wear ?

[Horserod]

I was told that you can tell if your touch hole needs replaced (or renewed) if your rifle's shot group starts opening up , all things being the same as type of powder, load, ball & patch & etc. Is there any other signs or tests to figure this out beforehand ? Is there a certain time one needs to replace the touch hole...such as after 500 shots or whatever ?? Thanks, Horserod

 

[Trench]

I was just starting to wonder the same thing on one of my rifles. I had drilled it out to 1/16th inch. I grabbed a 1/16 drill bit and it slid in snug, so I figure it's still okay.

 

[MikeChapin]

I usually change out the liner when accuracy starts dropping off and people 20 yards to right of me complain about getting sprayed.

I usually get three or four years of heavy use before things start going bad. I does depend on how much I opened the touch hole when I installed it. The larger touch holes seem to erode faster.

I have a .50 Tennessee that needs a new touch hole now. The rifle hasn't scatter shots but is shooting lower than it did. I had a dry ball a few weeks back and was able to trickle 4F into the touch hole by just tapping on the side of the stock. The stuff just fell right in. That rifle hasn't had a new liner for about 10 years. It usually shot so well that I didn't want to mess with it.

 

[ebiggs1]

When I first got my flintlock I put a stainless steel liner in it and bought several more. I thought I would need them as they surely wear out? I am three years later and 2000+ shots later and it shows no sign of wearing out. But if/when it does I am ready.
I can't see a liner “wearing out” will really destroy accuracy anyway.

 

[Flintlock58]

I had an experience where one of my flintlocks needed a new stainless touch hole liner because the amount of gas blowing back out of the touch hole did reduce accuracy. I should have measured how much the touch hole enlarged before I installed the liner. However, the liner solved the problem.

 

[David W.]

You should get a minimum of 2000 shots, most likely more. One note: The lighter the charge, the longer the TH will last.

 

[tg]

I believe the amount of internal coningand the resulting web profile will have a lot to do withn how fast the hole opens up,as well, I do not shot as much as I used to but the 1 1/16 at the breech barrel with a 5/64 hole coned a little on the inside will likly last a long time compared to a 7/8" barrel or even a 1" barrel with the same bore and vent/coning configuration. I suspect it is best just to shoot as normal and watch things untill a consistant change is noticed, then do an in depth study to find the problem so one does not replace or add a lner due to a bad can of powder.due to the different breech sizes and bore sizes and ways/depths of coning internaly and varying powder charges I doubt there is an "average" number of shots per hole so to speak

 

[Tom Compton]

I only noticed a drop in POI and that I was able to set on fire the cardboard I put up to keep from burning my neighbor. Several thousand rounds.

 

[Grizzled Roberts]

When you tamp down the load and you can hear powder hitting the leafs on the ground. its time to replace the liner. When you put the toothpick in the touch hole for cleaning, and the toothpick does not hit the sides of the touch hole, its time. If you shoot a lot you will see this every once and a while. An opened up touch hole will vent gas and pressure at an uneven rate. This causes uneven pressures in the barrel so your groups will be effected. Self priming is not good for a rifle.

 

[ebiggs1]

This sounds like a good next test for my chronograph. I am going to predict the variance will be tiny. Very tiny.

 

[Trench]

This sounds like a good next test for my chronograph. I am going to predict the variance will be tiny. Very tiny.

Are you going to drill one of your vent holes out too big? That would be interesting. Part of the issue would be an inconsistant charge if part of it is being blown out the touch hole. It does stand to reason.

 

[Tom Compton]

Enlarged touch hole can be kinda handy for charging the pan w/ FFFg but really kinda large when you are loosing FFg thru the vent.

in my case, the group was still about the same size just lower. When a percussion nipple wears out the shot to shot pressure seems to be greater. Always thought it to be based on how well or not the hammer stayed on the nipple.

 

[hanshi]

I have a couple of flinters that have seen heavy use. I always drill out the TH to 1/16" and check it from time to time. So far no noticeable change.

 

[Zonie]

Speaking of to big, there are many written comments about the shooter, back in the day, plugging the touch hole with a quill or feather before loading.

I have always thought that this stemmed from having a large touch hole in the barrel. It was a method of keeping the powder charge from blowing out of the touch hole while ramming the ball.

Assuming this idea of mine isn't far off base a fair test of large touch holes could shoot some rounds without the large hole plugged and with the large hole plugged during loading.

When I say "large" I'm speaking of something between 3/32 (.093) and 7/64 (.109) :grin:

Just a thought. :hmm:

 

[Many Klatch]

I have been shooting one of my rifles on a regular basis for at least 25 years and have not seen a need to replace the touch hole yet. Since I only shoot offhand I assume I wouldn't notice a slight change in POI if it did happen

Many Klatch

 

[Horserod]

Thanks to you all......I believe I have the info that I was lookin' for ! Best Regards, Horserod

 

[jethro224]

Another thing that could effect touch hole life, and I did not see it mentioned above, is;
how often,
how aggressively, and
with what you pick your touch hole.

 

[tg]

I do not see where a 1/16 hole will be any less cosistant than a 5/64 hole in batrtrel pressure a toothpick rarely works in a hole the size I prefer so I use a quill which was likley the way itwas done in the past I have not seen much in the way of records of toothpicks and the accuracy of the longrifle was well known in the past and not likley with a 1/16 vent hole we have gravitated to this size for sake of accuracy/efficiency over history which is fine if that floats your boat, I imagine that most folks from the past would raise an eyebrow if they saw the size of the holes on the new guns we make now
Many people now are going back to the larger holes of the past and doing quite well, it is just a matter of how closely one wishes to flirt with the experience as it was had in the past, I opened up one rifle to 5/64 and added about 5gr of powder as I recall and the same POA/POI were had as with the smaler hole, the "small hole requirement" is really not a requirement but a choice and probably best if going for super tight target competition shooting, then I do not see a "need" for liners on a new gun either, kind of like in the past as well.

 

[smoothy]

I had the same idea Zonie had about hearing how they used quills to keep the powder from coming out. Of course if you read "The Frontiersman" by Eckert it covers how Simon Kenton could load on the run without priming the pan, just simply hitting the butt on the ground while running to get the main charge to spill in the pan. Mark Baker also wrote about it. Maybe its all romanticism, but 200 years ago they probably didn't worry about the touch hole increasing in size over time as we do today. To address the original concern, its got to change pressures having a large touch hole, not sure about accuracy.

 

[Ray-Vigo]

I'm not sure what they did or did not worry about. What I do know is that when I visited the Baltimore Antique Gun Show a couple weekends ago I saw original flintlocks with a very, very wide variety of touch hole sizes. Some well-used military pieces had touchholes that had to be at least 1/8 or bigger. This was at the extreme end of the sampling I did, but I was very surprised at how much variety there was.

I expected it to be very much like the sorts of sizes we talk about here on the board, and many did fall into that range. However, quite a few had holes bigger than what we often see as guidelines here. There were a couple I would say that were smaller than the 1/16 we often see quoted too. But the real surprise of the rounds I made observing the guns closely was how many seemingly oversized touch holes were out there. I'm sure some were from abuse or wear after the period of primary usage, but I would imagine some were made with pretty big touch holes to start with.