Hair trigger

[snubnose57]

Just bought a used 1851. Good shape overall.
But, it has a hair trigger on it, more than I like.
Any tricks to fix this, thanks in advance.

 

[Phil Coffins]

I'd first check the trigger/bolt spring to see if it's been altered. Some times people will grind them down or put a shim under them. And even if the screw isn't tight could be part of it.

 

[hawkeye2]

Check the full cock notch and the nose of the sear (top of the trigger) for wear and the proper angles. It's also possible someone has lightened the mainspring excessively for a lighter pull. If that's so you will have trouble busting caps too.

 

[Mr. Troll]

Take the hammer and the trigger out of the frame and check the depth of engagement on the full cock notch. If it's worn, or virtually non existent, that will cause the problem. Sometimes people will do a "trigger job" and get carried away with polishing or removing metal. Parts kits are easily found, and depending on the year of manufacture, the hardening on the hammer may not be very good.Time to get to know the insides of your new acquisition.

 

[Zonie]

If you've never had a Colt apart, there isn't much to it. I do recommend putting the screws back into the holes they came out of after removing the part they are holding. Although the screws usually have the same threads on them, their lengths are a little different.

You do not have to remove the hammer screw or the hammer. Just remove the grip strap and the trigger guard.
While removing the trigger guard, I've found that often the mainspring can be pushed to the side to disengage the hammer. After doing this, the mainspring can be left in place.

When you remove the trigger guard, if the gun has the original trigger spring you should see it as a flat, two leaf type of spring.

One of the leafs works the trigger. The other works the cylinder bolt.

One leaf is slightly different in shape at the end of the leafs than the other and when you put things back together the spring must be put in the correct way.
If it is not, the trigger might not have any pressure forcing it forward.

In fact, that might be the problem with your gun so, the first thing I would try is removing the spring, turning it over and putting it back in place.
Then, without putting the trigger guard on the gun, try cocking the hammer to full cock and push forward on it.
It should lock into place at full cock.
The cylinder lock (bolt) should also have retracted as you started to cock the hammer and it should snap back in place with the end protruding thru the bottom of the frame (where the cylinder normally is) as the hammer reaches the full cock position.

Pushing forward on the hammer after reaching full cock, pull the trigger.
If the trigger feels like it should when the hammer releases, you've found the problem.

If neither the trigger or the cylinder bolt don't work right, the spring is upside down.

That flat two leaf trigger/cylinder bolt spring is known to break. Replacements are available from places like Dixie Gunworks.

Some people replace the spring with home made springs made from things like bobby pins and music wire. If they aren't made right, they can cause the problem you are having.

If there is nothing wrong with the spring, do as the others have said and check out the sear on the top of the trigger and the full cock notch on the hammer.

 

[snubnose57]

Found the problem, the tip of the trigger, where it engages the hammer, is broke. Ordered a new one.
Wondering about the hammer. The full cock notch is extremely shallow, like fingertip shallow. Is this normal? Thanks for everyones help!!

 

[snubnose57]

I meant to say finger nail tip shallow.

 

[Artificer]

NO, it is not "normal" for the full cock notch to be that shallow. Someone had to have filed/ground it down to get a lighter trigger pull.


HOWEVER, that is very likely the cause of the broken tip of the trigger that acts as the Sear. If the person who shortened/filed/ground down the full cock notch and did not shorten/file down/ground the half cock notch down enough, the "sear tip" of the trigger will hit the half cock and break the tip.

You probably will notice damage to the half cock notch of the hammer?

Gus

 

[snubnose57]

No sign of any file marks on the hammer . The half cock notch is nice and deep. Looking closer with a good light, the full cock notch is clearly there, looks just deep enough for the tip of the trigger to fit.

 

[Artificer]

Unless the hardening/tempering of the "sear nose" portion of the trigger was bad when the revolver was assembled, there really is no other explanation for that "sear nose" to be broken/chipped off other than it hit the half cock notch on the hammer as the hammer fell. I'm surprised there is no apparent damage on the half cock notch of the hammer, but that is possible and still it broke off the tip of the sear nose.

Normally when one presses back on the trigger and keeps pressure on it as the gun goes off, the sear nose of the trigger will or is supposed to clear the half cock notch to keep the tip of the sear nose from breaking as the hammer falls. That trigger press actually pulls (or should pull) the sear nose well away from the half cock notch as the hammer rotates when the geometry of the parts are made correctly.

I do something rather extraordinary when doing "trigger jobs" or lightening the trigger pull weight and adjusting the "feel" of the trigger pull and break. After I do a good deal of work to get the trigger pull weight feeling good and down to the lower pull weight, the last thing I want is for the sear nose to break off because it hits the half cock notch as the hammer rotates.

So before I put spring tension back on the Trigger and Hammer, I keep them in the revolver or other type of lock and very carefully hold the trigger with one hand and lightly pull on it while I use my other hand to put a little pressure on the hammer to mimic the pressure put on the hammer by the hammer spring. As soon as I pull the trigger just far enough to the rear that the sear nose clears or comes out of the full cock notch, I try to hold the trigger in that position firmly. Then I push lightly on the hammer and see IF the half cock notch clears the sear nose of the trigger as the hammer goes all the way down. If it does not clear the half cock and even if it just barely touches it, I modify/file down the half cock notch until it does not touch the sear nose held in this position. This can take a few times filing a little metal off the half cock and trying it in the revolver before the half cock notch won't hit the sear nose this way. Now the reason this is extraordinary is because when you normally pull on the trigger and keep it pulled back until the gun fires, you pull the sear nose further away from the half cock notch than that. I go for this little extra clearance between the sear nose and half cock notch in case the finger slips off the trigger during firing.

To visualize what I'm talking about, scroll down to Fig. 3 in the following link. This shows taking metal off the full cock notch to reduce trigger pull weight and taking metal off the half cock notch to ensure the sear won't hit the half cock notch. Though the part shown is a tumbler, the full and half cock notches on a percussion revolver hammer work the same way. http://www.nwtskirmisher.com/useful-locks.shtml

Now, I am not a fan of cutting down both the full cock and half cock notches when doing trigger jobs as shown in Fig. 3, I just am using that as an example on cutting a half cock notch so the sear nose clears it.

Gus

 

[snubnose57]

After looking at some online photos, the full cock notch looks a lot better than the one on my hammer. I now have a new hammer and trigger ordered. Just hope all goes back together with no issues. Since the gun is all apart anyway, I thought what the heck and ordered a new hammer.

 

[M. De Land]

The best method I have ever found to reduce pull weight and creep is to install a sear lift in the full cock notch which maintains the original hammer and trigger nose geometry.
Depending on the action type of rifle or hand gun I have successfully used pins or pieces of shim stock to limit full cock engagement.
I like the pin best.
Another method I have read of and yet to try is simply raising a burr with a prick punch on both sides of the hammer at the full cock notch bottom.
It crowds the nose of the trigger out of full cock notch engagement. It works the same as a sear lift, just lots easier to do.
New hammers and triggers need to be tuned up with a good stone and jig to insure they are square to each other and engagement surfaces are smooth.
The release edges should be broken as well to alleviate any burrs.
Check holes for proper screw pivot fit.
I like to make new trigger/bolt springs out of stainless spring stock as they virtually last for ever as compared to standard spring stock.
Once you get the pull down where you want and all creep removed then test with a raw hide hammer or block of wood smartly striking the frame below the cylinder on both sides to see if you can dislodge the hammer. It should not fail this test.
Don't strike the grip straps but only the solid frame as you can bend them.

 

[Artificer]

I have also heard of "raising a burr with a prick punch on both sides of the hammer at the full cock notch bottom," but probably like you - have never used it because it won't last long.

The most unusual/one of a kind method to keep the sear nose closer to the bottom of the notch was actually shown on an original, Post AWI Flintlock Rifle here on this forum within the past couple of years. It had a screw through the lock plate with a turnscrew/screwdriver slot on the outside of the screw. The part of the screw inside the lock plat screw was pointed, so screwing it in or out causes the sear nose to be pushed as far down the full cock notch as desired. When I first spotted that special screw on the photo, I wasn't sure what it was until I thought about what it would do on the inside of the lock.

I agree a hardened pin is one of the most permanent ways to set the distance on how far down the full cock notch the sear nose fits. The other way is to TIG weld a lump metal onto the hammer/tumbler, though I am not a TIG welder, so I've only done that once or twice.

I prefer using brass shim stock and low temp Silver Solder most of the time to fill up unwanted space in the full cock notch, because it keeps the cost low enough it is worthwhile doing for a wide range of civilian and military locks.

Many years ago I thought long and hard on making jigs/fixtures for all the Military and Civilian locks I worked on, but finally gave up on it other than to come up with a way to hold the sears at varying angles to get the sear face to agree with the full cock notch.

That was EXCELLENT advice you gave about ensuring the new parts have the unwanted sharp edges or burrs lightly stoned off of new/replacement parts. I keep two stones for doing that, both of them are 1/4 inch wide "Three Square" or Triangular Stones. One of them is an India Stone for smoothing rough surfaces and the other is a Hard White Arkansas stone for polishing.

Gus

 

[M. De Land]

I got that burr raise idea from Elmer Keith. He said he got it from a frontier gunsmith in Montana I believe. Keith says it is a permanent fix and worked perfectly on his single action and 1911 Colts.
I'm going to try it on one of mine next time I need to adjust one.

 

[M. De Land]

Kieth uses the term "Burr" but your actually raising a dimple on opposing sides of the hammer full cock notch that keep the trigger nose out of full engagement.
That leaves a rounded raised area at both sides that should never wear out.
It's such a simple and practical idea I wonder why it never occurred to me before reading of it.

 

[crockett]

I'd say off hand that the thickness of the nose of the trigger ought to be about the same as the depth of the notch. Fully engaged.
I would not do a dimple, shim, etc. as it seems you had that and want to go in the opposite direction.
One reason it is very difficult in working on triggers, notches, etc. is that the angles move in a circular direction so what looks like a right angle in one position can be less/more in another- if that makes sense. So avoid filing the nose or notch.
On your new parts, I think I would see if all works as far as the trigger and if so- then leave well enough alone.
I would buy a screwdriver and carefully grind it down to match the width of the bolt head and the thickness of the slot in the bolt- a perfect match- that way you can remove bolts without marring the bolt or gun.
As a general thing, on a percussion revolver- they get pretty dirty and need a good cleaning. Some folks do a minimum and seem to be okay but I always completely strip down the lock work, etc. and clean- so... You'll need to get familiar with that- it is really pretty simple.
There may be timing issues but hold off on that for now. The lock work/function on the later cartridge guns- Colt Single Action Peacemaker is the same as the percussion so any book on the Peacemaker can be more or less applied to the Percussion (some minor things but not much)

 

[Artificer]

Kieth uses the term "Burr" but your actually raising a dimple on opposing sides of the hammer full cock notch that keep the trigger nose out of full engagement.
That leaves a rounded raised area at both sides that should never wear out.
It's such a simple and practical idea I wonder why it never occurred to me before reading of it.

Hi MD,

With the varying amount of quality and thickness of the hardened surface/skin on many Italian Revolver Parts, I don't believe it would work well.

Further, those bumps raised would not have a clean 90 degree angle where the sear nose would come up against them. The Sear Nose would thus ride up a little on them when it settled against them. To me that means you would be introducing more creep into the trigger pull just as one begins to pull the trigger.

Now I could be completely mistaken because I've never done such a thing, but I don't think so.

Gus

 

[Artificer]

Your advice to get or grind a properly fitting screwdriver to loosen/tighten the screws is not just excellent advice, it is essential so as not to bugger up the screws or damage the parts around the screws. Someone else also recommended laying the removed parts out with the screws close to where they go in the revolver, is also essential for reassembly. A Fair Number of revolver screws are the same size threads per inch and even the size of the head, but the length of the shanks vary according to their intended use and that could cause problems if one tries to use a screw with too short or too long of a shank in the wrong hole. This from personal bad experience, BTW.

You are definitely right that the discussion of what was done to the hammer as it is in the revolver now, or most kinds of trigger work is not something the average person should attempt, when they are not that familiar with the parts and how they operate. A new hammer and new trigger, after any sharp edges or burrs are removed before installation, should or at least may make the revolver operate correctly again. A little careful “pre-smoothing” of the full cock notch and face of the sear nose on the trigger with a White Hard Arkansas stone would not hurt because it only polishes metal and does not take off any significant amount of metal, though this step may not be absolutely required.

The new parts will almost certainly cause a heavier trigger pull than what is on the revolver now with the modified hammer. There may or even probably will be more creep than now, as well. However, if the trigger pull is not that bad with the new parts, then for many people, it would be better to leave it alone or seek the help of someone used to working on these revolvers.

BTW, normally when talking about Revolver Trigger Work and since the Sear Nose of the Trigger is not that tall compared to other sears in other locks, there should be as much height of the full cock notch as the height of the trigger sear nose, if not perhaps a little more height of the full cock notch than the height of the sear nose.

Gus

 

[M. De Land]

Appreciate the discussion Gus and will give it a try then take some pictures of it to post. I think it will work very well and can be adjusted just as the pin or shim can be by stoning ,if necessary.
I really liked that it worked equally well on both single action or 1911 Colt hammers.

 

[Zonie]

I don't know why we are talking about ways to make the trigger pull lighter.

Snubnose57's problem is that the trigger pull is already too light. He wants to make it harder to pull the trigger.

His buying a replacement trigger and a new hammer is a good start and I suspect that after the new parts are installed, he will be happy.