Functionality of cut agate in flintlocks

[Larry Pletcher]

This has been a much cussed and discussed topic for quite a while. Currently we have two separate topics going. Shooters here have such wide experiences with cut (sawn) agate that I haven't seen an explanation that satisfies me. I don't like questions that cannot be rationally tested.

So leaving emotion aside, I went back some 25+ years and began looking at experiments that began at the Gunmaking Seminar at Bowling Green KY. I have two possible theories that I want to explore sifting through numbers from those years. The article containing the data is the Journal of Historic Armsmaking Technology, Vol. IV. Jan 1991.

Gary Brumfield was my partner in crime at the beginning. He prodded me into this study. Thanks Gary. The lock that took most of the experimentation was a large Siler with many modifications. (We chose to limit the trials of original locks because of their value.)

The Siler was timed in a variety of ways: multiple flints, bevels, and powders. Buried in this data, may be some answers to our current question.

I need more time to formulate my thoughts on this, but there has to be an answer in there somewhere. My gut says that frizzen hardness, stone hardness, or maybe both could be part of the answer. I need to go over some numbers.

Regards,
Pletch

PS if any of you have Vol. IV mentioned above you can see what I'm looking through.

 

[BE Wild Willy]

Thanks for taking the time to go through this for us. I'm in the process of acquiring my first flintlock and interested in your findings.

 

[hoochiepapa]

I was hoping we'd hear from you on this!!

 

[ebiggs1]

My personal reason for some factory guns using them is, they are uniform. That means they are easy to install. No one needs to know anything about a flintlock to put one in the jaws. Plus, they all seem to give a few strikes and that is all the factory needs. :hmm:

 

[jdkerstetter]

I have no personal experience with cut flints but I have read where some shooters have reported great success with ones imported from Germany, I.I.R.C.

Enjoy, J.D.

 

[Larry Pletcher]

The purpose here is to examine the reasons why sawn agate works for some shooters and does not for others. In looking back at research in the ”˜80s I found a series of trials done with both chipped black English and sawn agate. These opening tests show that this lock performs very well with both types of stones. Below is a brief comment with the flint comparison done in 1987-1988:

First a couple test comments. The lock is a very carefully tuned large Siler. The priming powder is Goex ffffg. Twenty trials were done for each series. Frizzen and flint edges were wiped between trials. Tests were done at room temperatures. Much was done in my school room on weekends.

Notice that the flint averages for bevel up and down are very close. Using chipped flints this lock doesn’t care which way the bevel is used. Bevel up is best when using the agate. Also note that with bevel up the agate was significantly faster than the other three test averages. Notice that the fastest trial was the bevel up agate (.0196 sec). This is so fast that the photo cell many have tripped on the light from sparks alone. For this to happen, spark production must be superb.

The times recorded here are very good. Any lock that approaches .0400 or better is very good. Lots of locks fall between .0400 and .0550. It should be no surprise that after this test, the bevel up agate looks like the way to conduct future tests.

Now, looking at the lack of success that other shooters have with sawn agate, one must ask why. Let’s first rule out sawn “soft stone” sold by some manufacturers. This stone is not in the flint family and isn’t as hard. The ability to sharpen a knife is not a valid test for a stone that sparks well in a flintlock.

I think we should assume that it is not the way the flints are mounted. We’re dealing with experienced shooters. Are we still missing something? The locks are the same brands in many cases. Are there variables we haven’t dealt with? I think there are two.

First are all these sawn agates exactly the same hardness? They are close but not identical. Are all frizzens exactly the same hardness? Are they all heat treated in the same batch by the same operator? No, they may be close, but not the same.

Dealing with the stones, flint, agate, chert, etc are part of a mineral group (complex silicates) that are number 7 on Mohs hardness scale. The scale is a 1 to 10 scale with talc at number 1 and diamond at 10. Steel is often thought of at 5.5. In a theoretical world all steel is 5.5 and all flint and agate is exactly 7. But, in the real world these numbers vary. All frizzens are NOT 5.5, and flint and agate are NOT 7.

I would guess that a mismatch of frizzen and stone could cause some of these problems. I have no way to measure the precise hardness of flint and agate, nor the exact hardness of frizzens. Maybe the Rockwell number system can help with frizzens, but I know of no way to get a finer number for the stones.

I guess I’m back where I started. My gut says the answer lies with the relative hardness of the frizzen and the stone. Swapping frizzens might be interesting. Perhaps a frizzen swap might make an agate-loving lock into an agate-hating lock. Regardless of which is the problem, shooters will continue to do as they have been doing. They will find the stone type that works and install it to best advantage. They will avoid the soft stone regardless if it is chipped or sawn.

Final thoughts: In geology class we used the stainless steel watch back to judge hardness in the field. If a stone won’t easily scratch your watch back, it won’t spark reliably in your lock. Don’t assume that any sawn stone is agate. Most likely it is soft sharpening stone. The sawn product from Germany is agate and performed well in my tests. The bevel up agate test was one of the fastest Silers I’ve timed.

I didn’t mean this to be this long. One idea led to another. I did decide to upload the JHAT article if the NMLRA will give permission.
Regards,
Pletch

 

[Matt85]

that was a good read, thank you.

i agree, it sounds like all saw cut stones are not created equal. an impure agate could be softer then one that is pure. while im very new to flintlocks, i do know a little about geology. its not uncommon for minerals and metals to find there way into crystals or precious stones. these foreign materials could easily reduce the hardness of agate or any other crystal.

-Matt

 

[Many Klatch]

I think the biggest problem with sawn agate flints is that they only come in one size. If you have a bigger lock they just aren't adequate.

Many Klatch

 

[Rifleman1776]

the biggest problem with sawn agate flints is that they only come in one size

Not correct. Being manufactured, they can be made in any size. Gunter Stifter in Germany sells many sizes.
The subject of this thread is a guaranteed :stir:
For the most part, I am on the "pro" side. I have had great success with sawn flints. (NOTE: I did not say "agate")
I used Gunter Stifter sawn flints with a Siler lock built in the 1970's for over 30 years. Ignition speed differences between chipped black were never even thought about. Igniton was very fast, that is all I cared about. They lasted a long time.
Gunters flints are made from several stones. They are listed on his website. http://www.stifters-gunflints.de/
I have seen comments that agate does not spark well. My experience is it does spark beautifully. Sometime about 1970 Darryl Waldorf, the well known knapper, gave me a hunk of red agate for fire striking. Great-great sparker. That hunk is now down to about the size of a quarter.
Back to gunflints. In my Siler Gunters sawn flints, of a variety of stones, sparked insanely and lasted a long time.
My current rifle is a Jaeger with a much hated Davis lock using their "improved" frizzen. Still a bummer. I don't have sawn flints large enough for this lock but have played with them in it and they spark fine. Using proper sized English knapped black flint life is terrible to moderate. But frequently they break in half. I have seen this happen in the past but as a very rare occurance. Now, using Fuller chipped blacks I almost expect it in this lock.
Putting this together, I conclude that a good sawn flint is a highly desirable sparker for our purposes. Of course, a lot depends on the type of stone.
In this crazy game of flintlock shooting, we are always trying to find the right combo of this 'n that to get the fastest and most reliable ignition.
I say, at least, trying goodsawn flints is an important part of that quest.
Final thought. Another gunflint seldom discussed is the sawn Novaculite. Same stone as the famous Arkansas whetstones. Reports on sparking ability and life vary from terrible to great. But, the general consensus is they are not liked. Earlier this year I considered buying in wholesale lots for resale but some preliminary market testing indicated they were about as popular as sewer rat stew :barf: . I did not make the investment.
Bottome line is, in the right lock, I love sawn flints. But, not nearly as much as I love the ongoing debates (arguments? :hmm: ) on this issue with ebiggs. :wink:
Just remembered sumptin'. A second "final" thought. :redface: I have a ceramic gunflint. It was sent to me years ago with a request to test and write a review on performance. Before I could do the testing the maker went out of business. I keep it in my range box as a novelty to show on occasion. Ceramic can be made to different hardnesses. I don't know how this compares to black flint, a 7, or most agate, also a 7. I also don't know if any are currently on the market.

 

[Grullaguy]

I have a lapidary trim saw in my truck that is on it's way to a friends house. He is mechanically inclined and the saw needs some work.

My intent is to cut a variety of the locally available flints and jaspers to see if any will be suitable as cut flints.

I will keep everyone posted as the experiment progresses.

 

[Rifleman1776]

I have a lapidary trim saw in my truck that is on it's way to a friends house. He is mechanically inclined and the saw needs some work.

My intent is to cut a variety of the locally available flints and jaspers to see if any will be suitable as cut flints.

I will keep everyone posted as the experiment progresses.

That would be fun. Do keep us informed.
We have a local lapidary club in my town which is a big retirement community. I have long looked for used lapidary equipment to come on the market after someone passes. But it never seems to. I believe it all stays within the lapidary club members.

 

[ebiggs1]

Mr. Pletcher you have more issues than just what lock or what frizzen the swan “flints” will work in.
You also have unreliable and unsubstantiated reports of how well they preformed in anybodies lock.
You actually don't even have a ground zero yet.
Unless folks can give you documented reports of their findings, it is just hearsay.
I find them so unreliable, I won't even try them anymore. Ole' Rifleman says loader up on yer birthday and replace it on yer next birthday.
Maybe he shoots once a year on New Year's Eve! :grin:

 

[larry wv]

I SAY not HEAR SAY that they work ok for me. Guess that means I am a nobody and my eyes are deceiving me. :idunno: Larry

 

[zimmerstutzen]

The thing seems to be that most folks with good American made custom gun type locks shy away from the cut flints. This could be a matter of lock geometry, tuning or even the alloy of steel (carbon content) of the frizzen, or the imfamous all of the above.

Of my flinters, I have several different makes of locks. Silers, Davis, L&R, etc all work well with english flints. The few locks with case hardened frizzens I have had, seemed to spark better with cut flints, even if for a very short life. Although, they easily chipped up both types of flints. Something I always attributed to the combination of case hardening and poor lock geometry.

The better lock frizzens don't get all scored up by either type of flint. But for some reason, they seemed to spark better with English flints. Maybe I was seeing what I wanted to see, don't know. I do know that in some locks, I get phenomenal flint life with English Flints. My North Star Trade gun had the same flint for hundreds of shots over several years of small game hunting.

Because of Pletch's experiment, I might give them a try again. It would be interesting to see if a case hardened frizzen demonstrates different results and or lives between the two types of flint.

 

[Larry Pletcher]

I knew when I wrote this that it would not solve the question I asked. Ebiggs, you're right about the ground zero idea. Anecdotal conclusions usually don't help in an experiment, even though they are easily offered.

One idea that floats around in my head is a camera test. A shooter takes a time exposure type photo of his lock with a chipped English flint and also a sawn (real) agate. The sparks in the photo could be useful. They would not tell why something doesn't work - only give evidence. Here is photo sample of the method above:

This is the lock that was used in the study in the 1991 article.

If money were no object, I would buy 10 locks from a maker and specify that all frizzens be heat-treated in the same batch by the same person. I would want a Rockwell number on the batch. Tests with a camera and both stone types might help to give answers. If further tests were useful, the 10 lock test could be repeated with a change in heat treating to a different Rockwell number.

The frizzen hardness is my "prime suspect". This is the reason I buy all my Silers from Jim C. My gut says that we, here on the forum, have frizzens made my multiple people, with different types of heat treating equipment, with multiple methods - giving us varying hardnesses. My last frizzen to harden was done by a smith who heated it in his forge, quenched it, and said, "Here, try this."

I think this flint/agate issue is a solveable problem; it only costs a bunch of time and money. Since that won't happen, I'll get my locks from Chambers and not worry.
Regards,
Pletch

 

[ebiggs1]

I SAY not HEAR SAY that they work ok for me. Larry

Doesn't matter how many shots you claim to get. I have no doubt you are getting along just fine with them. But if you can't document it, you can not use it as proof. And therefor can not establish a base line.
I generally document and photograph most of what I do so others can decided for them selves if it is worth it or not. There are just way too many variables in these tests to not write it down and keep records of exactly what was used, when and how it was done.

Guess that means I am a nobody and my eyes are deceiving me. :idunno:

This is silly! :surrender:

 

[Rifleman1776]

Ole' Rifleman says loader up on yer birthday and replace it on yer next birthday.
Maybe he shoots once a year on New Year's Eve!

Actually, it is a Leap Year, once every four years and I shoot every day. :wink: :rotf:
Who ye callin' "ole"? :grin:

 

[Rifleman1776]

The thing seems to be that most folks with good American made custom gun type locks shy away from the cut flints. This could be a matter of lock geometry, tuning or even the alloy of steel (carbon content) of the frizzen, or the imfamous all of the above.

IMHO, none of the above.
Sawn flints are not part of the culture of our current day shooters. Not likely the mountain men used them, or the backwoodsman, etc.
Sawn flints were more common with aristocracy in Europe who had fine guns custom made in cased sets. Gunter Stifter even offers a polished jewel-like flint for display purposes only.
My days of using them are dwindling down for several reasons. My Jaeger, with Davis lock, doesn't like them. (it doesn't like knapped English either, for that matter) Gunters flints are expensive and ordering from his web site is a challenge.

 

[George]

No one shooter's experience can tell you anything, of course, but I'll add mine. I have a batch of Stifter flints I bought in the mid 1990s, and I have been generally pleased with them. My overall impression is that they do very well when first put in, don't last like the black English flints I usually use, and are hard to sharpen. I have frequently gotten 100 shots from a black English flint, I never expect to do that with a cut flint. Most of mine are used in Siler locks, one from 1965, or so, the other from 1997. The guns I used to take my deer and turkey this fall, with those two Silers, both happen to have cut flints in them, just one of those things. If I ever run out of the Stifter cut flints I won't replace them.

Spence

 

[zimmerstutzen]

I did mostly match target shooting over the years. The way match shooters will tweak everything for the least little advantage, I would figure they would use cut flints if there was an advantage of any kind.