Siler Mainspring

[Finnwolf]

I'm trying to put this post together carefully so as NOT to step on anyone's toes. Everyone from the kit maker, to the builder to the lock manufacturer has attempted to stand by this product so far. However, my curiosity has got the better of me.

The topic is Siler mainspring breakage.

I have a new Siler lock that I bought a few years ago as part of a kit, disassembled into it's pieces in my workshop. When it was reassembled recently in a rifle, upon pulling the hammer back, it went limp and showed excessive play - broken mainspring.

The kit supplier sent a new mainspring to the builder from Chambers Flintlocks and the builder installed it in the lock and sent it to me. 25 shots later, the new mainspring broke at a most inopportune time.

I contacted the kit supplier again and he had Chambers send me a 3rd mainspring which I paid airfreight on (hunting season was about to end) and I installed in the lock. I sent the 2nd broken spring and some photos of the lock to the manufacturer but they cannot see a defect in either. Photo of the lock is below with 3rd mainspring installed.

I really want to develop trust in the lock but everyone tells me they've never seen this happen before in a Siler so I can't help but wonder if I have a defective lock - I guess only time will tell.

I wonder how rare this really is and, of course what the cause(s) could be (I think too much). Has anyone EVER had a similar problem with a large Siler flintlock? Anyone have a good idea what the likely cause is?

Finnwolf

 

[bob243]

it is more common to break a spring during sub zero temperatures, however not in the frequency you describe. I dont see anything that stands out in your picture either. What are you using to install the spring?

ETA is the spring breaking in the same place, if so where?

ETA2 in your pic, almost dead center it is real shiny, is something rubbing or hanging up there?

 

[redwing]

Back in 2004 I bought a TVM "Poor Boy" used. The rifle had been fired very little. I was shooting more than a few matches at the time. I put 1,000 rds thru the rifle over an 8 Mos. periode. I went to Az. to shoot a match near Parker, Az. The day before the 4 day event the lock failed. The large Siler had a broken main spring.. I had many people tell me it never happens to a Siler Lock. Well it did. I was able to get another spring at a Hellish price and shoot the match. After looking over the broken spring it was a wonder it lasted as long as it did. The spring had a bubble in the metal where it broke. Anyway true to form Barbie sent me a new spring, no questions ask. They are great folks. :thumbsup:

 

[Finnwolf]

it is more common to break a spring during sub zero temperatures, however not in the frequency you describe.
1st time it broke was in AZ in October at the builder's, not sub zero there! 2nd time was in 15 degree weather.

I dont see anything that stands out in your picture either. What are you using to install the spring?
I used a spring vise but I only installed the 3rd spring. I assume the builder uses same - he's built over 60 guns.

ETA is the spring breaking in the same place, if so where?
Don't know for sure, didn't see the 1st spring but the builder says it broke in about the same spot as the 2nd spring.

ETA2 in your pic, almost dead center it is real shiny, is something rubbing or hanging up there?I think it's shiny in the center of the lock plate because nothing much get's in there but I'll investigate.[/color

 

[Finnwolf]

I went to Az. to shoot a match near Parker, Az. The day before the 4 day event the lock failed... After looking over the broken spring it was a wonder it lasted as long as it did. The spring had a bubble in the metal where it broke.

Redwing,
Coincidentally, my rifle sat here in the northeast for about 3 years, seeing temps from about 30 in winter to about 90 in summer. My workshop is sparsely heated but doesn't get much under 45 degrees.
I sent the gun to a builder in AZ for about 6 mo. for completion. The gun came back to the northeast and I was out in about 25 degrees sighting in Oct/Nov and 10 to 15 degrees hunting in Dec/Jan. There was no "bubble" or casting defect in either spring. Rust was not a factor either. Can't guess at what the likely cause was.

Finnwolf

 

[David W.]

Is there a possibility your spring is rubbing against the lock mortise? Maybe it is in a bind and not allowed to work freely? :hmm: Is it hard to cock or feel like it may have resistance? I have never owned a Siler, but I have always heard they are pretty good quality.

 

[paulvallandigham]

It would help to see a picture of the broken spring.

The current spring looks very thick through that lower arm, and two thin at the base of the "V". Perhaps its just the shadows.

What kind of tension does this Mainspring put on the cock when its cocked back to the full cock notch? ( Put the gun on a bathroom scale, and read the dial for the weight of the gun. Then watch the dial as you cock the cock back slowly to the full cock notch. Subtract the higher weight from the weight of the gun to get your spring tension weight in lbs. Do this exercise several times, and average your results, as its easy to rush the cocking of the hammer, and jerk the scale heavier than it should be.)

I don't believe that Chambers does its own hardening and tempering of the springs in-house. Call them and ask, to be sure. It may be that your spring has a defect, or that the lock builder left a crease line in the lower arms, which caused stress at the spot, and lead to the breakage. Spring vises are nice, but on some springs, particularly if you are going to use them to close the spring( cock it) from a resting position, I believe you need to protect the contact points of the vise and the spring by putting tape on one or both surfaces.

If you use the spring vise simply to hold the spring at full cock to remove it to work on the tumbler, fly or hammer, where there is no movement of the spring arm against the vise at all, then you won't be causing any possible damage to the springs when the two mating surfaces are left bare.

There is one other possible problem, and that is if the spring arm is not made with an even, flat taper from the bottom of the V to the Hook at the other end. You can only see this kind of thing by a close examination of the surface with magnifying lens, or using a micrometer to look for bumps or thick( or thin) spots along the arm.

Any thin spot will create a weak spot for breaking later on, as instead of the full arm taking the weight of the tension as the tumbler turns, that thin spot will become a " hinge" that cannot stand.

Square edges on the sides of the spring arms can also cause weaknesses. A rounded edge is far more flexible, and therefore more durable. I take an India stone to the edges of the springs, to round the edges. It removes much of the unneeded tension on the springs, and makes them flex easier, without stressing the metal.

Those are my thoughts on what you have described. It is rare to hear of Chamber's springs breaking so frequently. I would not hesitate to find someplace with a microscope so I could examine the ends of the break on each of those springs to see what a microscope might show me, that I can't see with the naked eye. Most of the time, the location of the break is the best clue as to why the spring broke there, and not somewhere else.

Finally, new V-springs often benefit from being "broken in " in stages, rather than compressing them all the way to full cock, or more. This seems to be particularly so when the edges are square. From What I know of the metallurgy of Steel, this should not be the case. But, springs tend to work better, if they are slowly compressed, then released, and then compressed a bit more, then released, etc. The only other thing I have seen where this is the case is with straight, or " stick " bows. I can understand the need with materials made from organic fibers; I don't understand why this works with steel springs. :idunno: :rotf: :thumbsup:

 

[Dave K]

Personally, now that the deer season is over, I would send the lock in. Maybe there is something we don't see here in the pictures. But let the manufacture cycle that lock a few times and see what they find.

 

[Finnwolf]

Hi Paul,
Here's some photos of the 2nd broken spring. The 1st was installed by the builder and broke when he tried to cock the hammer.

The bathroom scale technique shows the rifle weighs about 7.5 lbs and the weight upon full cock is about 19 lbs.

I used the instructions on the MBS site and a spring vise to install the 3rd spring but I did not have to uninstall the 2nd spring -it was in 2 pieces inside my lock cavity.

I'll have to think about any modifications such as rounding the edges as they may affect the warrantee.

Jim did offer to cycle the lock if I send it to him. Seemed a waste of time then because I intend to take it to the range and cycle it myself under live fire conditions. I'll have to think about that as well.

Finnwolf

 

[Finnwolf]

Is there a possibility your spring is rubbing against the lock mortise? Maybe it is in a bind and not allowed to work freely?
Could be FL62 but I doubt it. The builder is a really good one. Anyone can make a mistake but I doubt it. If nothing else pops up, maybe I'll check with some lamp black.

:hmm: Is it hard to cock or feel like it may have resistance? I have never owned a Siler, but I have always heard they are pretty good quality.
This is my 1st Siler also, I've only owned T/Cs for 20 years before this. They were like toys compared to this hunk of machinery. This Siler does cock harder than a T/C but you'd expect that it would. More resistance than a T/C but I would not call it hard to cock.

 

[David W.]

Yes, Siler is a good quality lock. That's why I am puzzled. I see by the pictures that it is not in the bend as I would have otherwise thought. Even stranger where it broke.

 

[hanshi]

Springs are tricky. Any flaw, regardless how minor, can potentially cause failure. I own several Siler locks, both large and small and have not experienced anything like you describe. Until now I had never heard of a Siler mainspring failure. I'd be willing to bet you just lucked out and received two springs with flaws too small to see or diagnose.

 

[Finnwolf]

You may be right, Hanshi, it may be as simple as that. However, the reputation for quality, the lask of visible defects, everyone saying they've never even seen 1 break, and the 2 springs breaking within 25 shots has me asking questions though.

 

[ohio ramrod]

It may be where you are shooting it at. I owned a five acre lot once that was jinked. Every truck, tractor, or any other piece of equipmenmt that went on it broke! :yakyak:

 

[Finnwolf]

It may be where you are shooting it at. I owned a five acre lot once that was jinked. Every truck, tractor, or any other piece of equipmenmt that went on it broke! :yakyak:

Now why didn't I think of that? Since the first one broke in AZ and the 2nd one broke in PA, either those 2 places are jinxed or is it every place in between?

 

[David W.]

I have been wrong before, but by looking at where the spring broke, it does seem like it hit something. Springs do not usually break at the point yours did. And not one spring, but two. On top of that, it's a siler. I think it's time for the lamp black. IMHO

The only other thing I can think of is that the springs were hardened, but not tempered. :idunno:

 

[Tumblernotch]

I can't tell from the pictures, but are there any minute notches or file marks running across the spring where it broke? Even a very light scratch can start a break.

I've had the same mainspring on one of my (Bud) Siler locks for over twenty years without any problems. There's something odd here. As for getting two bad springs so close together, you may have simply gotten two springs from the same lot where the man doing the hardening had a bad day and forgot to draw the temper. That alone will cause a failure like that without any noticeable flaws.

 

[paulvallandigham]

I am thinking that Flintlock62 may have hit on the most logical explanation, because of the location of the breaks. Its quite possible that these springs were hardened but not properly tempered.

Have you ever dropped and broken a file?? These are hardened steels, that are not tempered on purpose. A look at the grain structure of the end of the broken file will give you an idea of what the structure of a hardened piece of spring steel will look like. Compare that broken file, to the ends of those broken springs, under good natural light, not florescent lighting. Use the best magnifier you have to aid in looking at the grain structure. The file and spring are made of different steel alloys, so there will be different sizes to the grain structure. But, I believe the appearance of the grain structure will be similar in the two broken ends.

I can't put it in words, but the grain structure in a Tempered piece of steel looks different. Perhaps Wick Ellerby, or Birddog6 can come on here and help describe the difference. There are a couple of other knife makers on the forum who are also quite competent to describe the difference in how the steel's grain changes when the steel is tempered.

I am surprised that Barbie didn't ask you to send the broken springs in to them, so they could examine them. If the work is being done by subcontractors, the Chambers need to know if they are being sold springs that do not meet specifications. This is obviously not something you can inspect with the naked eye, or over the phone.

As for worrying about breaking a warranty, the springs cost very little money. You simply cannot afford to hire an attorney to sue anyone for a breach of warranty over such a small item. You can't justify the court costs for such a suit. On Jim Chamber side of the issue, he can't afford the bad publicity of being sued, and its far cheaper for him to send you a new spring, than to argue with you about his warranty, and whether you somehow breached it. His time is worth more money to him, and his reputation is priceless.

So, do what needs to be done to tune that spring, and stop worrying about warranties. They are sales HYPE, in guns as they are in cars.( We also have implied warranties of Merchantability, and Fitness for purpose, which apply to all products, unless replaced with expressed warranties, in clear language, made know to the purchaser before the purchase is made. Not all notices are commercially reasonable.)

We have good people in this business, for the most part, and they are men of their word. They stand behind their work and products. Its very rare that we hear of someone who is upset by the way he has been treated by the vendors in this sport. It happens, which is why its so noteworthy when it does. :shocked2: :idunno:

 

[Finnwolf]

I can't tell from the pictures, but are there any minute notches or file marks running across the spring where it broke? Even a very light scratch can start a break.
I have only the photos left as well. The 1st spring broke at the builder's and I sent the 2nd spring to Jim Chambers to examine.

There's something odd here. As for getting two bad springs so close together, you may have simply gotten two springs from the same lot where the man doing the hardening had a bad day and forgot to draw the temper.
1st spring that broke was produced sometime over 4 years ago when I bought the kit. 2nd spring was sent by the kit manufacturer last October. It would really be odd if these 2 springs came from the same lot.

When I look at the photo of the lock, there does seem to be a shiny area in the center of the plate where the spring would make contact. There also seems to be a shiny spot on the spring where it broke. Could this be an indication that wood in the mortise it pushing the spring and causing it to rub the plate and break?

Finnwolf

 

[Finnwolf]

I am thinking that Flintlock62 may have hit on the most logical explanation, because of the location of the breaks. Its quite possible that these springs were hardened but not properly tempered.

Paul, I first thought it was tempering but it's not logical. The 1st broken spring was made over 4 years ago when I purchased the kit. The 2nd broken spring was sent to the builder a couple months ago. This kind of interval indicates quality problems that this manufacturer has never been associated with


I am surprised that Barbie didn't ask you to send the broken springs in to them, so they could examine them.

Jim did ask me to send him the 2nd broken spring and I did along with the lock photo. When I didn't hear back from him I sent an email. He emailed me that me he saw no casting defect and not being a metallurgist, he could not comment further. He offered to cycle the lock for me a few hundred times if I sent it to him.

As for worrying about breaking a warranty, the springs cost very little money.

The warrantee I'm worried about is on the lock. If something is wrong with it and a 3rd spring breaks, I will ask for a new lock under the warrantee.


You simply cannot afford to hire an attorney to sue anyone for a breach of warranty over such a small item.

I have no intention of suing anyone, I am simply looking for a logical explanation so that I can fix this lock and learn to trust the rifle.

I know I am dealing with the best components, makers and builders. I am not upset with anyone - just want to get the rifle up to speed.