Small Siler tuning

[Scota4570]

I am  going to use a small siler for my Armstrong pistol project.  The cock seem excessively difficult to pull back.  The actual pressure required is 13# of force as measured by a spring scale from the jaw screw head.  Based on my "calibrated" trigger finger the force required is over 20#.  I don't understand what is going on with that. 

The frizzen requires #3 of force to get it over the hump with the spring scale. 

Does this sound correct for a small siler lock?  My inclination is to weaken the mainspring.

[EC121]

Try polishing the tumbler and the toe of the mainspring.  Might help remove some friction.

[Jim Kibler]

Strong springs are a good thing.  I wouldn't weaken them.  Friction, binding etc isn't good.  Attack this potential problem.  I would make sure everything moves freely without the mainspring.  I'd also then polish the daylights out of the tumbler foot and mainspring tip.  Grease this, install the spring and try again.

Jim

[Stophel]

Beyond polishing what needs to be polished and making sure everything is working properly, look at the hook on the tumbler and it's relationship to the mainspring.  I don't think Siler locks generally have this problem, but some others do.  Depending on exactly how it was assembled, it could be that the hook surface is essentially too close to vertical when the cock is down...  Basically, when you start to cock the gun, the tumbler has to ram forward into the end of the mainspring and forcibly cam itself under to pick up the spring.  The hook should be more underneath the spring so that when you cock it, the tumbler simply picks up the tip of the spring without having to force its way around the end of the spring.  I don't know if that made any sense or not.  To solve this problem, the tumbler hook may need to be "scooped" out so that it slides more freely underneath the mainspring tip.  Of course, you can only go so far with this.  The mainspring may also have been positioned off just enough to cause this.

A properly shaped tumbler hook makes for a MUCH sweeter cocking action.

Honestly, though, I can't imagine that the Siler would be that bad, it has a fairly well designed tumbler, but it's something to look at.   

[flinchrocket]

A good picture of the internals might help locate your problem.

[Scota4570]

By comparison:
Large Siler #1     8#
Large Siler #2     12#
Kibler SMR          10#
Kibler Colonial     10#

I'll definitely take it apart and polish everything. 

I read about guidelines for a good flintlock.   I thought I saved it but can not find it.  It got into mainspring strength vs frizzen spring strength and balancing them. Also flint angle to frizzen at impact.  Basically what a good lock should be.   Ring any bells?

[flinchrocket]

Looks dry. You might try some lube.

[Scota4570]

There is no binding.  I polished and scooped the tumbler.  I polished the mainspring bearing surface.  I polished the tumbler and plate hole.  All areas to a mirror shine.  I then applied moly grease.  No real change. 

I have very strong hands and it is sketchy to cock it safely.  I'll have to see how it feels in the pistol. If I feel it is necessary from a safety standpoint I will thin the mainspring. 

Scot

[EC121]

It will be easier in the wood.

[flinchrocket]

Before you do anything to the mainspring call Chambers and talk it over with them.

[Dave B]

The main spring was installed too close to the tumbler or vise versa. The tip of the spring needs to be just at  the tip of the tumbler horn. Some almost look like they could slip off the end of the tumbler. The spring hook is binding into the upper shank at the axle  when you cock it. So your not lifting the spring any more you are compressing its long axis ramping up the force required to bring it to full cock. You can grind into the Horn axle junction so the spring tip has some where to go would help reduce the force needed. Other wise weld up the main spring pin hole in the lock plate and drill another one just an 1/8" to the left of its current location. That will bring the spring into its correct position. Some one other than Chambers built that lock i would guess.

[Scota4570]

I did what was shown in the sketch already.  I am getting a cam action that makes the largest force when the cock first starts back.  It is now around 12# at the start and 8# at full cock.  I will address the mainspring pivot hole when I make the new plate that is correct for the project. 

[flinchrocket]

After looking at these pictures I am wondering what the difference is in the length of a large and small siler mainspring. Wonder if you somehow got a large siler mainspring in a small siler lock?

[Scota4570]

That makes sense.  I got it this way as a gift of misc parts.  It is not marked by whoever assembled it.  A large siler has a longer cock and would require a beefier spring to get the same force on the flint.  I'll compare and report back.

Report: The spring is different than a large siler. 

While it was out I took a few thousands off the length and polished it all over.  It now takes 10# of force to cock.  It sparks very well.   Solved.

[EC121]

Even the large Silers have two different plates.  The new plates are about are about a half a hole off from the older one.  The new spring won't fit an old plate without welding up and re-drilling a new hole for the tit.