[Across The Pond]

Can anyone explain to me how to adjust the timing on an open frame Colt?
The bolt comes up too early - just a little - and is marking the blue on the cylinder. It scrapes the lead-in to the bolt slot, a fault I have seen before. Should I be lengthening the hand, or delaying the raising of the bolt?

Also, I guess I can peen the hand if it needs lengthening, but have no idea how to delay the raising of the bolt.....

Please help before I run out of gun blue cream!!
:confused:

[Old Fuff]

This can get a bit complicated...

If you remove the hammer you will see that there is a small stud at the bottom near the hole for the hand pin, on the right side. The cylinder bolt (the part that locks the cylinder in place) has a tail that fits over that stud. When you cock the hammer the stud lifts the tail, and that causes the bolt to drop at the front and unlock the cylinder so that it can turn.

As the hammer rotates backwards the little stud eventually slips off the end of the tail, which releases it so that it can pop up in time to again lock the chamber. The condition of the hammer stud, and the length of the tail on the end of the bolt, determines at what point the bolt will be released and, under spring pressure, pop up. If either the stud and/or bolt become worn, or if the bolt is poorly fitted, the bolt will be released early, and make the mark that you don't like. All of this may be straight forward, but the bolt also has to be "timed" so that it will be held down in the unlocked position as the cylinder is being turned while the loading process is underway.

One thing might be helpful. All of the Colt (and Colt reproductions) cap & ball revolvers use the same system as the later Colt Single Action revolver. There may still be some 'smiths around that know how to fix or tune a Single Action, and if they do they can also fix a cap & ball revolver.

On these kinds of revolvers, part are not "drop-in," as they are made oversized at some places and have to be expertly fitted to each particular gun. Whoever is still selling the guns should have a source for parts, and be able to point you in the direction or a qualified gunsmith. If you want to do the work yourself, you can - but in that case I'll have to point you in the direction of several "how-to-do-it" books.

[mec]

http://www.thehighroad.org/attachment.php?attachmentid=28908&d=1126823260

[RON in PA]

Maybe there is nothing wrong with your revolver other than your belief that there should be no ring when in fact a slight ring demonstrates proper functioning.

[Smokin_Gun]

All you need to do to lighten up the force of the bolt striking the cylinder is go in and back off the bolt/trigger spring say 1/8 of a turn or what ever amount lightens it enough for your taste...same as you'd do with the mainspring screw. There should not be a gouged ring in your cylinder, if there is it's hittin way too hard. One can carefully adjust the spring, but don't try to bend it too much it will snap. Use the screw adjustment first. Here's a couple pics of damage from a very badly installed from the factory bolt assy. on an 1836 Paterson. This case was a bit differant and the spring was installed incorrectly. Competely different than and 1851 Model Colt, but you get the idea.

http://tinypic.com/fxrxvt.jpghttp://tinypic.com/fxrxq9.jpg

[Across The Pond]

I have done some work on the .31 today - backed off the screw holding the bolt spring, polished the front, back and sides of the bolt itself, polished the return ramp on the cam, eased the mainspring a little too...

It's much better now - I am still getting witness marks but not the damage that I was experiencing before.

Thanks once again to all that responded! :)

[Across The Pond]

Those marks were getting to me.. On the basis that anything that's wearing the blueing off like that must be wrong, I got the '49 apart again.

I can see that the cylinder stop (bolt) is raising before the cylinder is rotated such that the the slot lines up (and before the hammer is at full cock). So I removed the hand and gently peened it to lengthen it. I couldn't possibly make it long enough that way, but it has proved my theory - that the problem is that bolt comes up early, rather than the hand being too short.

Next I lengthened the tail on the bolt - same way - such that it falls off the cam later. This has almost fixed it. Again, there's no way that I would keep peening the bolt to make it longer, so I have ordered a new bolt and will therefore be able to set the length correctly.

Now to a couple of questions:

What's the optimum profile for the top of the hand?
(Mec's post today on the Colt disassembly thread is very helpful in this
respect)

Once I have shaped the new bolt and the top of the hand correctly, should I harden them - and if yes, how?

[mec]

I'm not sure about the optimum profile- I just try to copy the angle and slope (and do so imperfectly) of the original part I'm trying to copy. Any effort at hardening and drawing the metal on my part would be a disaster, I'm sure. I haven't noticed inordinate wear on any of these parts that I have fitted or as they came in the guns and have not been aware of breaking through any surface hardening and encountering softer metal. In the case of the hand, it appears likely that the hand itself will certainly outlast the spring.

I added a post to the disassembly sticky thread above regarding several spare hands I just fitted. Once done, they fit both my Uberti 60 Army and my 61 navy. There are probably plenty of wrong and un-gunsmithly things about the way I do things but they work for me.

[Across The Pond]

Thanks Mec - I'm looking forward to getting the new bolt and fitting it. I am really enjoying learning to home 'smith the Colt. (it's finally getting cold here now, and sitting in the warm fixing my revo - with a glass of wine of course - is a pleasant way to pass the evening.......) I have even got a couple of hobby gunsmithing books on their way from the US.

The information posted here on THR is really excellent - I'm no craftsman yet, but I have learned to get my revolver fixed!! :D

[Beartracker]

Dave. Before you do anything else get a couple of hands so that you have them around just in case, They are cheap.
You are 100% right that you need a little longer hand.

Ron in PA. I have been shooting revolvers for many years in modern and black powder and I have never heard anyone say that you should have a ring around the cylinder if it's properly tuned. I may be wrong here and it wont be the first time but I prefer mine tuned to perfection without leaving any ring or mark and take pride in the fact that they don't and they run so smooth it's like they are running on ball bearings.It can take some time but it's worth it to me.

[Across The Pond]

Hi Beartracker - I will take your advice: and (with all due respect to Ron) like you, I prefer things to function as perfectly as possible... my '51 navy (in contrast to my currenly clunky '49) is so well set up that it sounds more like a watch ticking as you pull back the hammer! I think this is because a former owner has done the work properly following a failure - the cylinder bears the marks of past problems.....

Thankyou gents - will repost once the Dremel and the needle files have done their work!

Regards, Dave

[Tinker2]

I have timed a lot of BP and cartridge revolver from the
60’s on. I think that a lot of the advice that is posted
here in this post is outstanding. You should be able to
time it well using the above posts.

The only thing that I would say is that I normally buy new
oversize parts and fit them.

The bolt stop is tempered as a spring. If you must re-temper
it, do it like you would a spring.
I don’t harden the Hand. It is easier/cheaper to replace the
hand then the cylinder. I also replace the trigger/bolt stop
spring with one made of music wire. Doesn’t break as easy
and is easier to bend to adjust the spring tension.

Good Luck