Timing an 1860 Colt

Note: The contents of this thread were extracted from the following thread due to thread drift on my part.

https://www.thehighroad.org/index.php?threads/technique-to-remove-words-on-a-round-barrel.892353/



So I'm starting the timing. I did have to replace the hand as I broke the hand spring on the existing but I have retained all of the other internal parts even though I have replacements for everything. The new hand is visibly much taller than the original but seems to be the same shape as the original except the backside (hammer side) of the original appears to have been filed a decent amount.

Predictably the new hand over rotates the cylinder but other wise seemed to function normally when the cylinder was not locked in place except the trigger release was very light and there seemed to be two 'places' at full cock. The first being when the trigger/sear engaged in the hammer and the second an almost Impreceptively further pull of the hammer was when the bolt springs up with a noticeable 'click'. I found that there were occurances where I could not pull the hammer back when the cylinder bolt had engaged the cylinder and the hand (maybe I should be using the term pawl) was tight against cylinder. And I assume that will diminish/go away as I trim off material from the top of the hand(pawl). Does that make sense?

Here is my plan for going slow. I have transferred the hieght of the existing hand onto the new hand. I didn't measure it but that distance would take quite a few strokes with one of the corser files. I then marked a single width of a fine magic marker on the top as my first stop point. This thin line is about 15-20% of the visual difference between old and new. I intend to file only that much off and check the fit again and repeat as necessary. I will stop filing when the action works even if it is much taller than the original.

I could never make a living at this, but I try to 'do no harm'.

kje54 said:

Some of the older reproductions as well as some Piettas and the current Ubertis have a slightly short arbor. There are lots of fix discussions on other forums which for obvious reasons I can't link here on this forum. Search for "uberti short arbor fix".

Click to expand...

I have read about thaat issue regarding the Piettas. But I wont attempt to fix something unless there is an indication it is broken. Remember I did fire this thing back in 2016 and it seemed to function properly.

It's a good thing I don't have to make a living off of my skills or lack thereof. Below are two pictures one is a comparison of the old hand to the new. The other shows two lines drawn on the new hand. The lower line is an eyeball transfer from the original part. The Thin Line on top is how much I take off each pass. At this rate I'll be done on Friday. Although the old hand appeared to work before I broke the spring, I do not know for sure if the size of the original end is correct. So I go slow.

What I find is that the hand is tall enough that it trys to rotate the cylinder before the bolt has dropped out of the way and binds the cylinder in place.

I am becoming concerned that I am close to having the hand the correct length but I still can't draw to half cock as the cylinder is locked and the hand wants to immediatly rotate the cylinder before the bolt has a chance to retract.

Is it possible that the hand needs to be trimmed so as not to protrude as far into the back of the cylinder? Maybe bend the spring for a little less tension?

Here is a comparison of the old and new. The small amount left to be trimmed off the top of the new hand is commensurate, to my eye, with the amount of over rotation I have left to correct. But it seems to me that I will be able to reach the correct length of the hand and still have the cylinder locked as described above.

I am suffering from a bout of cerebral flatulence regarding the timing relationship between the hand/pawl starting the rotation of the cylinder and the bolt drop. The hand/pawl is now the correct length to rotate the cylinder to the correct position. I can check that by starting from the half cock position. But as soon as I start to pull the hammer back from the fired position (hammer down, bolt up) the pawl/hand is in contact with a ratchet and begining to try to rotate the cylinder. But the bolt has not yet dropped yet and I end up in a bind.

If this animation is correct,



there should be some upward movement of the pawl/hand before it contacts ratchet. It seems to me if I shorten the pawl/hand to give it some room to travel upwards before it touches the ratchet, it will then be too short to rotate the cylinder to the correct position.

I know I'm missing something.

I have gathered some thoughts on the binding issue and am working a proof of concept. I'll address that in another post.

In the meantime I devised a repair for the original pawl. I drilled and tapped for a 2-56 screw and made a replacement spring from a old magazine follower from a Turk Mauser I no longer own. It functions as it did 5 years ago. It has a distinct 4 clicks. But it does work. The spring is undoubtedly stronger than the original or needs to be. But it too can be adjusted.

Time is relative. Although I'm in the "not buying green bananas" part of my life, I'm in no hurry to figure this out. Although I am very close with the new pawl, I don't want to make the final cut on it until I understand the relationship between the pawl and the bolt. Jackrabbit and I are going to speak tomorrow and I have put myself on hold since Friday trying to understand that relationship better.

In the meantime the 'fix' for the broken pawl spring looks like it is going to last. So this weekend all I have been doing is working on the timing using the original parts and inserting the new bolt and spring and seeing how those parts Interacted differently. Both of which need some fitting. The original parts work pretty well and initially ended up with 4 distinct clicks. In fiddling around I learned that spring tension impacts the timing of the number of clicks heard. By reducing tension on both the trigger/bolt and mainspring screws I now have only 3 clicks. Though sometimes I hear a double click on the 3rd click. Still pondering that.

Johnm1 said:

spring tension impacts the timing of the number of clicks heard

Click to expand...

It may impact the timing, but at least in this case it doesn't last. Repeated cycling must 'loosen' things because after a period of time I'm back to 4 clicks. The gun is from the mid-70's and was pretty beat up when I got it. So who is to say that threads haven't gotten 'sloppy' over the years. It's interesting to note, but not necessarily the answer.

I spent some time on the phone with @Jackrabbit1957 tonight. Very insightful conversations and I am grateful he is thoughtful enough to share his experiences. I have a bolt guide to fabricate and then some time trying to implement what I learned tonight.

In a nutshell adjusting an older/worn bolt is not intuitive.

Thanks again Jackrabbit1957.

The time on the phone with @Jackrabbit1957 has returned success. The bolt guide is fabricated and installed and the bolt modified to drop the bolt quicker and solve the binding issue. This is with the repaired original pawl.

It still has 4 clicks but cycles correctly now. I think the next thing to tackle is the excessive cylinder gap.

The cylinder gap is now reduced from 0.030" to 0.015". I did have to take some off the arbor and taper that cut to get this far. I find that the wedge i have is a bit too small now. Inhave a replacement i ordered 6 years ago with the other parts but can't find it. I tried to peen the existing wedge but I can't move enough material to make it tight. I made a shim from that old Mauser follower to hold things tight temporarily. After I acquire a suitable wedge, I will reduce the cylinder Gap further.

As with everything I do, I learned a few things in this last operation. I didn't want to Mar the locating pins on the frame. So I elected to reduce the end of the barrel instead of the frame to reduce the cylinder gap. I know now that was a mistake. After I made the first reduction and tried to fit things and measure, I noticed I was going to have to fit either the locating pins or their respective holes, or both. I decided to sacrifice the locating pins so I could measure accurately. As it turns out, even though the surface of the pins were marred I was able to reverse the pins and Salvage them. I wish I had started with the pins removed and worked on the brass frame instead of the steel barrel. Lesson learned.

Another oddity. The action parts have been assembled throughout the Cylinder gap operation and were assembled with 4 distinct clicks. A problem to be addressed later. Other than cycling the action (I like the sound of the clicks) nothing has been done to the action. Yet this morning I find there are only 3 clicks. Figure that?

I spent the day trying to fit the new parts. As it turns out, the new bolt is unusable as it is too short and releases the bolt prior to the full cock notch. I don't see how it can ever be used as the legs would have to grow longer I think. I tried the new hammer and Trigger combination but the hammer is oversized and I am not comfortable messing with that geometry. I suspect it would be another two weekends just to figure that single relationship out safely. The new hand will be usable. I just need to understand how the final cut to length will work with the initial bolt drop that I have timed right now. It appears I might need to re-time the bolt rise for the new hand and I am not willing to do that at this point. I have a hand that works properly and clocks the cylinder correctly while the initial bolt drops timely enough to prevent a bind.

I may have figured out the Oddity regarding the number of clicks changing. The repaired hand works well, but the new spring screw does loosen over time without a thread lock. This is the only thing that I know that changes while the gun is together. I locked the threads with nail polish today and will monitor the condition. Once I get some thread lock I will lock it with that.

I am pondering the timing of the bolt rise. It seems the leg either has to be shorter or thinner. For now I have four clicks. But, the additional distance of the hammer pull does rotate the cylinder to its final position. If I knew how, I would time the full contact notch to engage sooner. I'm not sure that is possible.

BBBBill said:

The lockwork seems very similar to the Colt Single Action Army. Do you have Kuhnhausen's book - Heritage Gun Books - Colt Single Action Revolvers Repair and Maintenance Manual ?

Click to expand...

Unfortunately no. I really should though. That seems more 'polite' than leeching off of others hard earned knowledge. In my defense I'd have a thousand dollars in books I'd only use once.

BBBBill said:

Leeching? No way.

Click to expand...

I know, many, including you, have been very generous with sharing your knowledge. And I do appreciate it very much. Not being in the business I could have bought the books for quite a few project guns that I have worked on. But I'd never have a use for them after finding exactly what I was looking for though.

And I agree, there is a pleasure of reading them.

In general I have 4 clicks. 1. Half cock 2. Full cock 3. Bolt pops up 4. Bolt drops in the slot as the hand pushes the cylinder into its final correct position. The cylinder is held in place by the bolt and there is no tension from the pawl. ie. I can rotate the cylinder the amount for the amount of play between the bolt head and the slots on the cylinder. Not much, but I can tell there is no other force acting on the cylinder.

But, something appears to change over time as I have cycled the action a lot to see if the timing changes. Well that and it is just a neat sound. I have not disassembled the unit since the above observations but at the moment I have 3 clicks. 1. Half cock 2. Full Cock 3. Bolt pops up directly into the cylinder slot while the cylinder moves into the final position. But, I can tell that the pawl is still pushing on the cylinder. There is no movement of the cylinder.

I don't observe any peening on the cylinder but I have some more observations to confirm that. The gun is an older model ASM I think from the 70's. There is no date code on the firearm but I think it is the 70's or 80's. Things get old and loose. Like me. Now the one thing that might change is the tension the wedge imparts on the barrel. From the above descriptions I have removed 0.015" of cylinder gap and the current wedge just isn't big enough to do its job correctly. I currently have a small leaf spring on the barrel side of the wedge so the sedge will impart enough force to hold the barrel on tight. I do have a new wedge on its way but maybe the spring tension of my current workaround loses some tension over time. Though I can't see how that would impact the timing.

Does anyone have a idea of what changes over time?

As I ponder the final timing issues, I noticed the end of the barrel. What the heck can I do to this to make it look like something other than a hacksawed end of a cut pipe?