Timing troubles, Hammer cam or bolt?


September 6, 2008, 06:44 AM
I have a Pietta '51 Colt repro. which has timing issues.I ordered a complete rebuild kit with springs,hammer,trigger,bolt,hand,etc.I've installed all the new parts but still have to push the hammer forward with my hand to reset the hammer/bolt or the cylinder will stay locked.I know I need to do some filing/fitting,but I don't know whether to do it on the bolt or hammer cam.I have two good hammers but only one bolt,my thoughts are to file the hammer cam on my old hammer.Also I've filed all the way through on the hammer to "fix" my high shooting colt until I'm looking at the frame and I'm still shooting nine to ten inches high at twenty paces.I know these guns are suposed to shoot between wind and water but is there a replacement tall front sight or should I learn to silver-soldier?

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September 6, 2008, 07:58 AM
Having a little trouble understanding your description of the problem.

You say you have to push the hammer forward to 'reset' the hammer/bolt or the cylinder will stay locked. Where in the cycle is this push forward required - hammer down, half cock, or full cock?

Generally the bolt is the part that needs modification to fix timing issues. The hammer is hardened and thus more difficult to file. The bolt is softer metal and less expensive if damaged or the filing is overdone.

You should be able to watch the action parts interact to determine where and how much filing/stoning to do. Remove the grips and trigger guard, turn the gun upside down and use a good strong LED type light to illuminate the interior as you cycle the hammer and trigger slowly. It helps to loosen the mainspring retaining screw to soften the hammer blow and slow things down.

If I understand your description there may be a burr on either the hammer cam or bolt spring leg that's preventing the leg from slipping back down to it's starting position on the cam. Very little filing should be needed to fix this.

Another possibility is that the trigger/bolt spring retaining screw is too tight. You might back it off a half turn at a time and see if that helps.

Sometimes bending or straightening the leg of the spring that contacts the bolt is necessary. Perhaps the spring leg isn't strong enough to return the bolt leg to it's proper initial starting point on the hammer cam, in which case bending the spring leg might be what's needed.

Re: the sight problem. Filed "all the way through" to where? Again, the hammer is hardened, so a significant amount of effort would be needed to remove even a small amount of material. Filing the hammer notch is not often productive in correcting this 'characteristic' of the Colts. Unfortunately, there are no readily available aftermarket front sight fixes; people generally make their own out of a brass rod and solder it in place. Far more often people just learn to use an exaggerated six o'clock hold.

September 6, 2008, 12:56 PM
i have said it before and i will say it again. It May be useless for you for now. But when you have a bp gun. Its important to order a parts kit all internals. When you get the parts kit. Take your gun apart and file the new parts so they look just like yours. Mark the new parts with a sharpie so you dont confuse them. Then replace the parts one at a time making sure the gun works everytime you change a part. So that eventually you should have all the new parts in the gun and the original parts on the counter. Check to see it works. Maybe take it to the range Just once. Then go home take the gun apart take all the parts and put them in a baggie and label it for that gun. Put your original parts back in of course. do this for all your guns. This way when ever you have problems you will not only be able to quickly replace the items in question but you will have working replacements. Just make sure if you needed to use the replacements that you order new parts and do it again.

Now i have an 1851 pietta. a few weeks ago i noticed it was having timing problems first time ever. At the end when you pulled the hammer all the way back the cylinder would turn too much. almost 1/4 of an inch more than it needed. Well after cleaning and taking apart the gun and putting back together. I tried it again nope didnt work. So i pulled out my replacement bag. and tore apart the gun. Turns out the bolt needed to be replaced. So i replaced it and ordered a new one. When that one comes in i will make sure it gets filed down to fit in the gun then put in the parts bag. Then replacement bolt once i put it in and put the gun back together. Works perfectly.

September 6, 2008, 09:58 PM
Thanks to Scrat and Mykeal,more details sirs, with the hammer all the way down I push it forward to reset the bolt.I've bought the full replacement parts kit after buying a gun with a little timing trouble so I couldn't make a duplicate part.I can visually see the problem and I wanted to know what you guys thought I should do.Yes sirs the hammer is hardened! I wore out a triagular file depening the sight notch.How deep one of you asked, not hardly to the hammer face that contacts the cap. So,,,,I should slowly "sneek up" on the bolt, filing a little at a time giving it a try every couple of strokes.My original bolt was damaged on the spring side not locking up the cylinder every time, when I disassembled the gun the bolt was noticeably damaged and the cylinder was marked in an odd way, not the drag ring I am accustomed to but "dents" where the bolt was not dropping in at the right time.The new bolt fixed the lock-up problem but with the hammer all the way down I put a little pressure on the hammer and the bolt will reset.I've owned two Remingtons and one Colt and have been all over them and haven't had bolt trouble with any even with a very high mileage Remington you guys helped me with welded nipples.

September 6, 2008, 10:17 PM
you got it right. carefull slowly filing. dont take much off you need to perfect the part. its going to take a little time. file a little then try it out. once you get very close you may want to try sand paper a very very fine grit. 400 or so you got to do it slow so that your honing it along. as soon as you get it right order a new bolt and make a duplicate. In fact the other parts in the revolver do the same while you have working samples.

September 7, 2008, 04:39 AM
Your hand is too long/wide it locked up the cylinder, the bolt won't drop cause the hammer won't move and visa versa...file & stone the parts to match the old ones then polish them and reinstall... best a luck, One more thing , did you bevel the bolt leg that hits the hammer cam so as it won't gey stuck at the face of the cam...don't file the cam, 1) you shouldn't it will damage it, unless you are stoning off burrs. 2) always file/stone the inside bolt leg.(or the cheaper to replace parts)


September 7, 2008, 01:56 PM
Hope these help

September 7, 2008, 02:10 PM
Xlint Joat, good posting ... every forum needs more like this.


September 9, 2008, 11:52 PM
Joat, that was marvelous....Where did you find this?I especially liked the coil spring and plunger mod. using Ruger parts.

September 10, 2008, 12:52 PM
Awesome thread the best ever

September 10, 2008, 08:41 PM
with the hammer all the way down I push it forward to reset the bolt.

Does anyone else wonder how you could push the hammer forward when it's already "down"? On the face of it, it sounds like a logical impossibility. Is something causing the hammer to hang up?

That Pietta tuning article says the Pietta hammer often binds against the frame. Mine did, exactly as noted in the article. When the gun was dirty I had the exact same problem-- I had to push the hammer forward to reset the bolt. Since I shaved the inside of the frame to make room for the hammer, this never happens anymore. Look for wear marks on the sides of the hammer or on the inside of the frame cut.

There are other problems that would cause the hammer to hang up. A misfit mainspring is another one.

I bring this up because over the years I've seen literally hundreds of repair attempts that were addressing the wrong "problem".

September 10, 2008, 10:37 PM
Searching the web was where I found it and I am still compiling information for other projects in home gunsmithing. Come to think of it I found this place on the web, just goes to show you that some good can be found, just got to dig for it.:rolleyes:

September 10, 2008, 11:03 PM
Ive had a Pietta giving me fits. I bought a parts gun that arrived lacking all of the screws and hammer, No internal parts. I tried to match one of the seven spare hammers I have. I finally ordered parts and they fit like a glove. I am going to check that bolt cyl notch more from now on. Thank you Joat for your article.

September 10, 2008, 11:40 PM
I wound up filing just a hair's width off the spring side of the bolt.I think I had enough play on the hammer screw to allow movement enough for the bolt to reset.I will also check my frame for the problems you mentioned.Joat?I figured it was on the web,where specifically?Thank you to all involved in the quest.

Old Fuff
September 11, 2008, 08:59 AM
I suppose the Old Fuff should consider writing a book…

‘Cuz there is no way I’m going to be able to cover all of the issues that have been brought up in a single post, so a lot of things are going to be left unsaid as I just cover some high points.

During the 19th century when these revolvers were first made, things were done a lot differently then the way they are today. A lot more skilled hand work was involved, and no one expected parts to simply “drop in.” In fact triggers, cylinder bolts and hands were deliberately made oversized in certain places so that the factory final assembler or outside gunsmith would have material to work with while doing the necessary individual fitting. The practice of making these parts oversized continues today, because in Italy they still hand fit the guns as was done formally, but not always with the same skill and attention.

It is therefore imperative that replacement parts be those made by whoever made the gun, and the gun owner should understand that experienced fitting is still required.

Sometimes problems associated with the bolt are caused by a worn cam/stud (called the “hammer cam”). In the original revolvers the hammer cam was a separate part that was press fit into a hole in the hammer. Both the hammer and cam were case hardened, and the surface was harder then a bankers heart. Today’s replica hammers are investment cast, with the cam being part of the casting. Many, if not most, are not hardened to this degree, although the hammer is colored to make it look so. How can you tell? If the surface can be cut with a file it isn’t case hardened. As the bolt is spring tempered it can soon tear up the softer cam - unless the lower part of the hammer is case hardened after any fitting or adjustments are done. It essential that this be done before the hammer sees much use.

As I mentioned above, as it is shipped the bolt is not a completed part, but a blank. The probable cause of MISSEDSHOT's troubles is that the left side of the bolt’s tail isn’t beveled, nor has the tail been shaped to release the bolt in the lede of the cylinder notch. As a result the bolt may pop up either too early or too late. If you cock the hammer and let it fall it will go all of the way, but may break the bolt as it does - so don’t do this. If you lower the hammer gently the tail of the bolt will get hung up on the stud until you push on the hammer hard enough to force it to go the rest of the way. Correct fitting of a bolt is a story in its self.

You can use the original part as a pattern to shape a new one - but if the first part wasn’t right you will end up with two wrong parts.

Times up! I’ll be back later.

September 11, 2008, 11:51 AM
good post Old Fuff. Your always welcomed here

Old Fuff
September 11, 2008, 04:07 PM
good post Old Fuff. Your always welcomed here

The Old Fuff is in the middle of nowhere, and having all kinds of computer problems - especially with making connections. I could get better service by hooking up to a fence wire. :cuss: :banghead: :banghead:

As a consequence I will be off and on, and probably more off then on.

Replica cap & ball revolvers are such a pain... but they are so much fun too... :)

The Italian revolvers keep getting better, but at the same time the importers keep demanding more for less money, and in the real world things don't work that way.

Once upon a time in a world now gone there were no replica or reproduction C&B revolvers, so if you wanted to shoot one you had to get an original 1800's gun. I wanted to so I did, as the cost was nowhere as high as it would be now. This being the case I got to shoot 1849 Pocket Models, 1851 Navies, 1860 Army's - and even a Dragoon... :eek:

Somewhere in the bunch some Remington's cropped up too. :uhoh:

Dixie Gun Works supplied us with parts, some of which dated back to the 1860' and 70's; and there were men left that knew how to rebuild them because their fathers or gandfathers (and sometimes both) had worked at Colt's factory during the middle-later 19th century.

So I was able to learn, and learn I did.

But the times just ain't what they were....

September 20, 2008, 10:23 AM
I've got the bolt working properly and fitting in the notches on the cylinder the way it should.My problem now is the hand/arbor area.When you go to half-cock, turn the cylinder alittle, then go all the way to full-cock the cylinder sometimes does'nt rotate and lock up.I know, replace the hand/spring.After doing this I have the same trouble.In investigating this problem, with the barrel and cylinder off, I watched the hand come out of the window and it contacts the arbor in the machined area too much causing the hand to go up instead of out and up, thus missing the timing spurs on the back of the cylinder.My question is, should I bevel the hand so that it slides over the arbor smoothly or further polish/bevel the machined area on the arbor?I just bought another Pietta '51 with the same half-cock,spin, full-cock,no rotate issue.Two guns, same problem.

September 20, 2008, 01:08 PM
id really have to see it myself but i would suggest polishing it out

September 20, 2008, 03:26 PM
Sounds like the Spring either got compressed, or not bent out enough to push the hand out. Burrs or roughness inside frame where hammer slides, polish or smooth it up in there spread handspring and try again. Be sure hand isn't too wide in slot and polish it too.

Hope that helps,


September 20, 2008, 03:38 PM
buy some replacement parts quick. then once you get this figured out. make some replacement parts that will work and function in your gun then save them.

September 20, 2008, 08:26 PM
Fellas, I already bought a new hand and installed it, same thing,I took it out and put the old one back in.The reason I said something about beveling is because of some hand I saw Mike c. [MEC] do for a Walker.

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