Thoughts on frizzen spring pressure and flint longevity?

[BCRider]

I attended a Rendezvous this past weekend and had a great time. Didn't do all that well but that's my own fault. But it was great just to be out and shooting some smoky stuff with the flintlock.

One of the guys in my shooting group mentioned that he has gotten up around 100 or so shots from the one flint he was using. I was blown away by that as the best I've managed is around two dozen or slightly more before some slight edge knapping was needed.

I got to check out his Brown Bess and found that the frizzen on his action had a surprisingly soft spring and that it really only sprung closed for about the last 10 to 15° onto the pan. The rest of the travel it would just sit there and let itself be easily pushed this way or that. And with only a few ounces of pressure too.

This contrasted with my own frizzen. On mine it snaps shut firmly up to 20 to 25° from seated on the pan. It just sits in the other spots but needs a firm pressure to move from one angle to another in either direction.

Now the first concern is that the weak pressure on his frizzen spring might allow the frizzen to avoid riding the flint with enough pressure. But this does not seem to be the case as he generally has very good reliable ignition when I've been out with him on a number of occasions. In fact he's the fellow that taught me a few tricks about shooting flintlocks in light to moderate rain.

The bottom line is that I think I'm going to lighten up my frizzen spring a little and play with the heel profile where it rides on the frizzen spring to ease up my own lockwork. I don't think I'll go as extreme as his until I get or make a replacement frizzen spring to play with. But I feel there's much to be gained with this sort of frizzen spring tuning. If I were able to get up to more like 50 to 60 shots from a flint before it needs a bit of edge knapping I'd be overjoyed.

Thoughts? Your own findings?

 

[yonderin]

Looking forward to your results. I'm no mechanic but the process of the strike wouldn't seem to make that much difference to me if you did lighten the spring pressure. But your hard experience would over ride my guesswork.

What kind of gun are you using? I have a Renegade that chewed flints (particularily the sawn ones) so I went to musket sized flints with much more satisfactory results. Suggests to me that the more massive flint equals longetivity.

Since I went to the larger flints I've wondered if the shape of the ones I used previously was part of the issue. Usually ended up with a big percentage that were humpbacked to a greater or lesser degree. The bigger ones don't generally have as pronounced a hump on them. Maybe the profile helps it stay in optimum position and reduce flint wear?

 

[BCRider]

I've got two flintlock rifles. One is a Lyman GPR (my first) and the other is a custom built job by a west coast fella named Al Brown. Sadly Al isn't with us any more but he built a lot of rifles and smoothbores that are still in regular use by a lot of the western region shooters.

I posted the same question on another forum as well and a reply from a long time flint fan suggested that I was on the right track. He basically said that we really don't even NEED a spring other than to hold the frizzen shut over the pan and to hold it open so we can prime the pan.

He also suggested that some of the main springs are far more powerful than needed and smashing the flint into the frizzen with that much power doesn't do us any favors either.

I went ahead and profiled the cam on the frizzen after I'd cleaned the lock and barrel from the weekend shoot. I should also mention beforehand that the frizzen spring in this case has a small roller wheel so the other fellow's suggestion that the end of the spring needs to be shaped as well as the cam didn't really apply in this case.

What I aimed for was to re-profile the cam so it has a circular arc segment through the mid travel which has its center in the middle of the pivot pin hole. So I actually Dykemed the cam and used a compass to scribe such an arc. The hole was packed with a slip of wood to let me put the tip of the scribing compass right in the center. A couple of tries to fine tune the results and now I've got a frizzen that snaps down from around 20° lift but past that to nearly fully raised it will sit in any spot I leave it and pushes easily with only moderate drag. Then it finally snaps open right near the end of the lift like it always did.

It's not as easy moving as my buddy's by a long shot yet. But it's far more easy to move than it was before.

I've also got a Lyman GPR flint lock. That one used to eat flints like kids eat popcorn during movies. I doctored that one up to match this one some time back and it helped a LOT. The GPR used to get around 12 shots before I'd have to knap the edge to freshen it up. Now it gets up around two dozen before any flint knapping is required. The Al Brown custom made flinter has always gotten up around two dozen shots from a flint before anything is needed. And with this new tuning I'm hoping for a lot better performance. And if it works out as hoped I'll go back and match up the GPR

The fellow that's tuned a lot of locks also mentioned that in stock form the mainsprings are similarly overly harsh. We aren't trying to run the hammer at speeds needed to fire a cap or primer. And his claim is that the hard mainsprings smash the flints against the frizzen and chip away a lot of the flint faster than is desirable. And indeed my Brown rifle does have a very stout mainspring. I'm OK with easing it a little. But I think this is going to be my excuse to build a leaf spring tool for servicing the main springs without damage to them. So tuning the main spring will be Chapter 2 to come in a week or three.

 

[mooncoon]

I fall in the category of feeling a good lock should fire without a frizzen spring. I think that lock geometry has a lot to do with flint longevity. The best I can do with a Siler lock is about 60 shots per flint or about 20 shots per knapping. I also feel you should think in terms of starting with the bevel up when the flint is long and bevel down as you knap it shorter. I think you want the flint to first strike the frizzen at a bit of an angle. I would not weaken the mainspring because the faster the #### strikes, the duller the flint can be.

cheers mooncoon

 

[LeroyvdH]

Interesting thread.. I'm reasonably new to this only a couple of years.. Started with a TC Hawkin 50 chews through flint.. Bigger flatter flints work better 20 - 25 shots.. Got a Lyman GPR 30 shots with an agate still not bad condition.. My TC shamuses into the frisson GPR seems more gentle.. I've only played with angle more than anything.. will be following along
Leroy

 

[stampede]

I fall in the category of feeling a good lock should fire without a frizzen spring. I think that lock geometry has a lot to do with flint longevity. The best I can do with a Siler lock is about 60 shots per flint or about 20 shots per knapping. I also feel you should think in terms of starting with the bevel up when the flint is long and bevel down as you knap it shorter. I think you want the flint to first strike the frizzen at a bit of an angle. I would not weaken the mainspring because the faster the #### strikes, the duller the flint can be.

cheers mooncoon

Me too. Bevel up for the first 10 or so strikes or until the edge shows significant chipping , then knapp and bevel down for another 20 or 30.

Each make of flintlock will have its own geometry and requires some experimenting to see what works.

 

[BCRider]

Right, so leave the mainspring alone for a faster strike and more sparks. But lightening the frizzen travel/resistance is ok.

Leroy, if I thought it would help and if I had a replacement for that now useless Photo Bucket account I'd put up a picture of the cam nose from the GPR to show you what I did. But the reality is that so little metal was removed and the shape changed so little that I seriously doubt either of us would see the difference unless they were compared side by side in real life. But there's no doubt that the easing of the cam on the GPR made a big difference.

One thing I did notice on the GPR was that the wear on the frizzen before I modified the cam was occurring in waves along the face. After the modification and a re-facing to remove much of the waves the wear is far more even with long consistent scratches along the face. So that seems to be one source of proof that the initial mod was a good one.

I've got a few things to do the next couple of days but I'm hoping to get out and try the Al Brown a bit later this week and I'll post up comments on how well it turns out in terms of good sparking and consistent ignition.

 

[Dsiwy]

Not sure if you ever need to nip a Bess flint? Shot 80rds so far on one flint and it's beat up ass hell and shorter, but still working. Maybe beginners luck lol? I really don't know, It seems to be nip its self during impact.

The flint made some dents in my frizzen early on when it had a knife edge. But gave even scratches once the edge got bigger. I might nip the edge off the next flint I install. Also my flint came wrapped in lead, if that makes any difference?

Also I always spray my frizzed and flint with break-clean before firing, this way the metal/rock is free of oils.

 

[Ol' Flinter]

Mooncoon, Stampede and I are on the same page. The frizzen spring's purpose is primarily to keep the frizzen closed over the pan. Lock geometry and the hardness of the frizzen will determine how long your flint lasts between knaps. The flint is not intended to "strike" the frizzen so much as to scrape down the face and shave off microscopic particles of white-hot steel to ignite the powder. The longer the scrape, the more sparks you get so changing the bevel can really help. As for main-spring power, a flint #### is heavier than the percussion equivalent so needs a stronger spring for speed and to forcefully scrape the flint down the frizzen. I would not weaken the mainspring.
Locks with poor geometry or a wrong-size flint will eat flints at an alarming rate whereas a proper size flint in a good lock will seemingly go on forever. With the frizzen closed and lock set at half ####, the new flint should clear the face of the frizzen by about 1/8" or 3 mm. Bevel up or down as gives the best scrape travel.
Good luck.

 

[mooncoon]

One thing I did notice on the GPR was that the wear on the frizzen before I modified the cam was occurring in waves along the face. After the modification and a re-facing to remove much of the waves the wear is far more even with long consistent scratches along the face. So that seems to be one source of proof that the initial mod was a good one.
.

Ripples or waves on the face of the frizzen slow down the flint, I think. I have no idea on how many strikes it takes to form those ripples but I feel they reduce the sparking of the frizzen. Fortunately, a 6" grindstone is about the same curve as many frizzen faces and you can bring the face back to smooth by cautiously grinding it smooth. I have an original East India bess lock that had a great hollow in the center of the face from repeated use of small flints, I suspect. It would not spark at all but after grinding most of the hollow out and recasing the frizzen, it sparks well now.
Many locks, particularly Italian and Spanish locks use case hardened mild steel parts and if you grind the frizzen face of those, you should expect to have to recase the surface at the same time. Not as radical as you might think because by the time that the frizzen has become rippled, on those locks, the flint has probably already cut through most of the cased surface

cheers mooncoon

 

[BCRider]

Well, there's no doubt that smoothing the cam motion on the GPR helped both in terms of eliminating the waves in the frizzen as well as reliability of ignition. So I think you and the rest are onto something about the speed of the #### falling and how it should have a good turn of speed.

To eliminate the smashing of the flint into the frizzen I'm thinking that setting the flint so it hits sooner in the fall would be a good thing as long as it doesn't needlessly raise the impact point on the face of the frizzen.

I've seen a lot of recommendations for using lead as the padding for the flint instead of leather which gives too much. I think that'll be my next "upgrade". Up to now I've just used leather to pad the flints.

The only European flintlock I've got is an Armi Sport. And that quickly broke the tab off the mainspring. In looking at replacing it I found so many issues in the lock that your suggestion that it might also have "just" a case hardened frizzen would not surprise me at all. It's a nice looker but it's VERY cheaply put together inside. For just one example the lock does not have a bridle. So even with some careful fitting the #### and tumbler wobbles around in a most horrible manner. It's so bad that I'd forgotten that I have it. It's so bad that I've sworn off Armi Sport and the parent company of Chiappa in all ways.

 

[infideleggwelder]

would this type of tuning work on a cheap Spanish lock? it looks like a CVA. I had to tighten up the frizzen spring because it wouldn`t keep the pan closed. this lock also seems to prefer beat up and dull flints, as it wont spark well until the flint is beat up and dull. it is really good at making them that way too. it likes some of them in sideways bevel down as well, so in theory, I could use all 4 sides if the flint. it has a very strong spring, and I also suspect the frizzen could be harder. it is not mounted on any gun, I got it in a trade where I think I got the short end of the deal.

what do you use to case harden , and where do you get it?

 

[mooncoon]

what do you use to case harden , and where do you get it?

the common case hardening compound is Kasenite and can be purchased from Track of the Wolf or from Dixie. It pays to buy several small things at the same time if you are buying from those companies because they have a significant shipping and handling charge.

The older version of Kasenite that I used to use was black in colour and would melt into a bubbling puddle. Times and formulae change I guess and the Kasenite that I bought a couple of years ago was more of a grey colour and while it does melt, that is not particularly obvious because a dry crust remains on the surface. To use it, I sprinkle a generous amount on the frizzen and heat the frizzen red hot from the opposite side and keep it red hot for 3 minutes at least using a clock. Three minutes is a long time when you are standing there holding the frizzen in the flame. I also add more Kasenite if the portion on the frizzen appears to have burned away. Finally drop the frizzen into water to harden the surface. I normally sand the surface bright and reheat the frizzen to golden to dark brown before installing it on the gun. My impression is that a frizzen can be too hard as well as too soft. For no very good reason, it is my impression that carbon penetrates the steel at about .001" per minute at red hot. It does not just instantly penetrate. Also you need a good heat source; I use a oxy propane cutting torch but I suspect you can also do the work with a Coleman stove. Another alternative is to build a retort or sort of open ended box to contain the heat while using an ordinary household propane torch. Think in terms of 2 fire bricks for sides another across one end and either a brick on top or a piece of concrete asbestos board if you can find some. Sit the frizzen face up on some sort of non combustible pedestal (a metal one would rob heat) and shoot the flame of the propane torch into the box and onto the frizzen

cheers mooncoon

 

[Ol' Flinter]

An alternative to trying to gold plate your Volkswagon would be to spend about $150 USD and buy a proper replacement lock "RPL" from Track of the Wolf and be done with the fiddling around. The RPL locks are made by L&R and are specific to fit particular guns. What is your time and frustration worth...

 

[infideleggwelder]

I think of that too, but I do like screwing around with stuff. like I said, this lock does not have a home. it sits on the bench and when I get bored I mess around with it. it never used to spark at all, and if I ever modified it to spark reliably, it might get a stock to call home. for now it is just a distraction.