How long do modern locks last?

[Darkhorse]

I ask this for personal knowledge. The lock in question is a LH Large Siler that's on my .54 deer rifle. This rifle has a single trigger. I built this rifle some 20 years ago and it has been shot a lot over the years. The lock has never given me any trouble, shoots fast with good ignition. It has been a good lock.
In the last few years the shooting duties have mainly been taken over by my .40, and the .54 is mainly shot before deer season. So a few months ago I was checking my guns out and noticed there wasn't a fly in the lock.  I must have overlooked it because I found it in my spare parts box. With deer season approaching I put the fly back in the lock and a wooden flint in the jaws to do some dryfiring.
I pulled the trigger and noticed the trigger pull was much lighter and the engagement much less than I remembered. I got a trigger scale and tried to cock the rifle again but it would not stay cocked. It felt like there was no engagement at all.
I changed the sear spring to a thicker one and it made no difference. So I removed the sear and it looked a little battered at the engagement end.
Next I swapped the sear and the tumbler from the .40 into the .54 and used a new sear spring. That fixed the problem and gives me my deer rifle back to hunt with.
So what I want to know is it normal for these 2 parts to wear like this after 20 years? My locks are well maintained, washed after each shooting session, oiled lightly and I use grease on the bearing points.

[Bob Roller]

Probably case hardening that is worn thru after a lot of shooting.Recut the full cock
position and touch the sear up and then reharden them. OR,contact Jim Chambers
and get both parts new and install them and use it another 20 years.Neglect and lack
of preventive maintainence will ruin any mechanism small or large but I don't think
you have neglected this lock.It's "high mileage" and wear can be expected.

Bob Roller

[Mike Brooks]

Never have seen any of my locks wear like that. I have seen a lot of frizzen wear on a couple that had 10' of thousands of shots through them, but they still worked fine.

[bob in the woods]

I have a large Siler lock which has gone  over 20 thousand shots  .   I replaced a broken main spring once [ deer hunting in minus 30 deg . Saw a deer, brought the hammer to full cock and the spring broke. There was an air bubble in the casting . ]  Chambers sent me a new spring.   The lock functions perfectly, although I was thinking of replacing the frizzen which is well worn.  Silers, in my experience , have variations in consistency, depending on who assembled them. The ones purchased directly from Chambers can be depended on for quality.

[BOB HILL]

A lot of Siler locks were built from kits by others.  How well they were heat treated has a great deal to do with wear.
 Bob

[Dan'l 1946]

Never have seen any of my locks wear like that. I have seen a lot of frizzen wear on a couple that had 10' of thousands of shots through them, but they still worked fine.

I have Ron Long Denver locks and a Schillinger lock that are 40 plus years old and well used that look new and fire reliably every time. I have never had a failure with any of my Chambers locks. Always got them from Jim.       Dan                                                                                                                               

[Darkhorse]

A lot of Siler locks were built from kits by others.  How well they were heat treated has a great deal to do with wear.
 Bob

I think this is my answer. The only other problem I've had with a lock was the one on my .40 caliber, it is a Large Siler also. I was Turkey hunting (legal here) and called up two toms, I cocked the rifle and the mainspring broke. End of that hunt. When I got home I called Chambers and it turned out they had gotten a batch of improperly heat treated mainsprings in and some had gone out in assembled locks. They sent me a new mainspring and I also ordered an extra while I had them on the phone.
Knock on wood but I haven't broken another mainspring. So far.

[G_T]

With a single trigger on that lock, the fly was not needed. If, when the lock was built, a track for the fly wasn't put in place on the sear, it is possible the fly chipped the sear when it was added and the lock tripped? I find the flies are generally oversized before being fitted. Though, I have a lot less experience than many here.

Alternatively, the trigger smacked or snagged while at half cock? Or dropped into half cock? That can also break a sear particularly if it is tempered a bit on the brittle side.

Or having the height of disengagement of the sear from the tumbler full cock notch be lower than the half cock notch and something prevented the trigger and sear travel from achieving clearance? The fly handles that on a set trigger of course. But the years without a fly could have caused a passing nick each shot?

Gerald

[hanshi]

A small Siler I had on a gun gave me fits with unreliable ignition and a "catch" that served to lighten the strike of the cock.  The gun had a single rather than a dbl trigger.  I removed the lock and examined the workings closely.  It appeared to me that the fly was the problem.  So the fly was removed and the lock worked like a champ.  I don't want a fly on the lock if the gun has a single trigger.

[Darkhorse]

The lock came with the fly installed and was used that way with a single trigger for almost 20 years. It may have had 10 or 15 shots without the fly. I want a fly on all my locks single trigger or set triggers, the fly helps prevent the trigger from snagging. Sometimes when checking the trigger pull with a gauge a lock without a fly can snag. This is because the hook on the gauge lets off pressure when the lock trips, sorta like set triggers.
I can see no sign that the sear chipped and I examined it closely under magnification, however I did not examine the tumbler so closely but I did examine it and the only odd marks were on the sear. I described it as "a little battered", actually that may be stretching it a little. On one half of the sear tip the metal looks "upset" but not really battered. Sorry that's the best description I can give as it's a small thing.
My shop is still not usable after Hurricane Micheal but it's getting there. Once I get set up again I can examine that sear and tumbler better, and for practice I'll see what I can do to fix it. In the meantime a new sear and tumbler will be ordered for the other lock.

[alacran]

I have only had one lock that gave me trouble with wear. It was a small Bailes. The fly rides against the lock plate. The fly itself was thinner than the gap between the plate and the tumbler. This caused the fly to not always move flat against the plate. The fly being hardened, it eventually wore a trough in the plate. This caused the cock to sometimes stop at half cock upon firing. It only took about 2000 shots for that to happen.
Welded up the trough in the plate and made a thicker fly and that fixed the problem.
For a period of five years I was  shooting about 100 shots a month. Half of that in practice the other in competition. That only comes to 1200 shots a year. In five years that's only 6000 shots. That would be 24,000 in 20 years. If you only shot one gun at that level of use.
But like a lot of us I shoot many guns. for different games.
When you think about it it is uncommon for the average shooter to wear out a lock.

[Bob Roller]

I recently got a lock back for "fly" replacement and it shows a lot of shooting if
the frizzen is any indication.It's a Ketland that I made in 1983 and other than the fly
which I have replaced,the mechanism is as it was when it was shipped all of those
years ago,strong and fast.It is obviously a well used and well maintained lock.
If a lock is inspected once in a while and cleaned and screws checked for tightness
there is no telling how long it will last if it was a good lock to start with.
Bob Roller

[Darkhorse]

Every time I  shoot one of my blackpowder rifles the lock is removed, cleaned, dryed, reoiled and regreased. Then checked for function before it goes back on the rifle. It takes  me a half hour or so to clean a rifle as  I am very thorough and single minded about my guns. This lock has not been abused, shot dirty or shot dry since the day I bought it new.
So I am a little perplexed at the cause. My best guess (from an old toolmaker) is that the sear was heat treated but not quite hard enough, which allowed over time some material to be pushed out of shape.

[G_T]

Well, I'm working on a lock where I have heat treated the sear twice. Initially the sear was getting chewed by the tumbler. Now both are chewing each other. It is slight, as I am using a microscope for inspection. But neither surface is tough enough, even when starting semi polished and greased. It takes only a short while to start the scarring process. Given enough shots, this would wear down these parts. I'll be case hardening both to try to improve the surface hardness, this coming weekend. Anyway without microscope inspection I would not have known.

Gerald

[Darkhorse]

I got a closer look at at the sear and tumbler today. There is some definite wear on the end of the sear but I can't see nothing on the tumbler.
How do I draw those parts in order to file them? Then how do I heat treat them back? All I have to work with here are a oven and a torch, and I'd have to find the torch as it's boxed up.

[Frank]

Just send it to Jim Chambers. He will fix it up for you and it will function as new.

[jerrywh]

To sum it up, It depends on who is shooting it.

[Darkhorse]

Jerry, I have listed my normal practices concerning my locks. What, in your opinion, am I doing that has caused this lock not to hold at cock anymore? If I need to change something I need to know what it is.

[hanshi]

Darkhorse, in the case of the single trigger/lock problem mentioned, the fly was positioned lower than in any lock I've had experience with; that likely was the issue.  Without the fly it operates smoothly and reliably.  My smoothbore has a single trigger that is light/crisp and reliable.  The lock is one of those large Chambers locks.

[Waksupi]

Well, I'm working on a lock where I have heat treated the sear twice. Initially the sear was getting chewed by the tumbler. Now both are chewing each other. It is slight, as I am using a microscope for inspection. But neither surface is tough enough, even when starting semi polished and greased. It takes only a short while to start the scarring process. Given enough shots, this would wear down these parts. I'll be case hardening both to try to improve the surface hardness, this coming weekend. Anyway without microscope inspection I would not have known.

Gerald

If the hardness of two parts are too similar, they will gall.