1860 Colt Army Pietta repro.

[Leon DeGamme]

I own a 1860 Colt Army reproduction made by Pietta. I have noticed that lately the cylinder stop has been gouging the cylinder in a way that I am not sure is normal. I know that wear and tear in this area is to be expected but this is a pretty deep gouge. Does anyone else have this?

 

[mykeal]

That 'gouge' is called a cylinder ring and they are quite common. They occur when the cylinder is rotated with the bolt not fully retracted. That can happen for many different reasons, including a worn or broken trigger/bolt spring or a poorly timed bolt leg or hammer cam. A common cause is taking the hammer to half cock, manually rotating the cylinder and then pulling the hammer back to release it from the half cock position and lowering it onto the cylinder. Any time the hammer is in half cock it should be pulled all the way back to full cock to move the cylinder into battery before lowering it.

 

[Tommygunn]

Looks to me that the bolt isn't (A.) timed quite right and (B.) isn't shaped properly where it's hitting the cylinder outside of the anticipation notch.

 

[FSCJedi]

A common cause is taking the hammer to half cock, manually rotating the cylinder and then pulling the hammer back to release it from the half cock position and lowering it onto the cylinder. Any time the hammer is in half cock it should be pulled all the way back to full cock to move the cylinder into battery before lowering it.

Can you elaborate on this? If you aren't suppose to rotate the cylinder at half cock, how else are you suppose to load it?

 

[Leon DeGamme]

the cylinder does have that ring that is caused by the bolt riding it and I know thats pretty much normal. What I am talking about is the notches that the bolt fits into. It seems that the bolt is hitting it a little too soon when I pull back the hammer before it slides perfectly into the hole. Because of this, its causing the notch to become slightly deformed. Other than that, the cylinder lines up correctly with the barrel when the hammer is fully extended and locked back. I am mostly wondering if its safe to keep shooting it?

 

[Bad Flynch]

Here is what I see:

The main cylinder bolt notch and the tapered slide-in notch that is called the anticipation notch are just fine. However, there is a ding on the side of the anticipation notch and that is not normal.

Ordinarily the bolt first contacts the cylinder in the anticipation notch dead center. In an ideal world, the bolt would drop directly into the bolt notch, but it is hard and time-consuming to get it so that it is exactly there every time, hence the anticipation notch.

The bolt top is apparently off-center and, according to the size of the ding, the bolt may be a little high. Take it to a competent revolver smith, that is what I have had to do and the results are well worth the money.

 

[mykeal]

FSCJedi said:

If you aren't suppose to rotate the cylinder at half cock, how else are you suppose to load it?

Sorry I wasn't more clear. I did not mean to say that rotation of the cylinder AT half cock was a problem. The problem is when people attempt to release the hammer from half cock and go directly to uncocked, or fully down on the cylinder.

At half cock the bolt is retracted; at both full cock and uncocked it is not. If you pull the hammer back from half cock into full cock, the hand rotates the cylinder to line up a cylinder notch with the bolt, and the action is timed to drop the bolt into the notch when the hammer reaches the full cock sear. You can then release the trigger and gently allow the hammer to return to the uncocked position; the bolt will be in a cylinder notch and no 'damage' will occur.

If, however, one pulls the hammer back just a short distance out of half cock, releasing it from the half cock sear, and then allows it to fall forward into the uncocked position, the hand does not move the cylinder. The bolt is free to move, in fact, it's forced to move, from the retracted position back to it's "up" position, where it would normally find a cylinder notch. Since the cylinder has not been rotated by the hand into a position where a notch lies above the bolt, the bolt contacts the cylinder surface, producing the scratch known as a cylinder ring.

This condition is not a safety issue; it's more a cosmetic one.

In the case cited in this thread the nick in the side of the notch is indicative of a timing problem rather than a handling one. The problem is corrected by modifying either the cam on the side of the hammer (least desirable solution) or the leg on the bolt that rides on the cam (more desirable solution). It's a delicate modification requiring removal of small amounts of metal at specific locations and is best accomplished by a gunsmith familiar with the Colt Single Action Army action.

However, it can be done by anyone who is reasonably handy with files/stones. I'd recommend buying a couple of extra bolt assemblies (about $3 each) so you can make mistakes and have something to start over with. The modification is described in several gunsmithing texts and involves removing metal on the inside of the curve of the bolt finger that contacts the hammer cam.

I don't believe there is a safety issue in this case. The cylinder is in battery despite the slight misalignment of the bolt with the notch. Even if there was a slight misalignment of the chamber with the barrel forcing cone the effect would be a slight shaving of lead off the ball. This would be apparent by the collection of lead deposits on one side of the forcing cone. Accuracy would naturally be affected, and cleaning would be a problem, but little else.

 

[Leon DeGamme]

I found a reference here regarding how to adjust the force of the bolt hitting the cylinder http://www.thehighroad.org/showthread.php?t=166920&highlight=adjust+timing. It mentions "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." I am not sure what this means exactly, can someone explain what he means by "back off the bolt/trigger spring 1/8 of a turn? or bending the spring?

 

[mykeal]

Yep.

Read the article, "How to disassemble a Colt revolver" under the sticky thread "Black Powder Essentials" at the head of the index for this forum.

When you get to the point where you remove the trigger guard you will see a slightly curved piece of metal that has two fingers extended toward the back of the gun. It's held in place by a fairly large screw at the front of the slot under the trigger guard. That screw is the "trigger/bolt spring" screw; the piece of metal it holds down is the "trigger/bolt spring". One of the fingers rests on a small ledge machined into the trigger and the other rests on the bolt fingers.

Loosening the screw an eighth turn will result in less spring force on the bolt itself, and in turn less force on the cylinder by the bolt head. It will also cause the screw to be loose, and the spring force on both the bolt and the trigger will not only be lower, it will be inconsistent as a result. It will also result in premature failure of the spring. I do not recommend this method of lessening the force of the bolt on the cylinder. In fact, I am at best skeptical of the whole idea of lessening the bolt load; any problems with the bolt impacting the cylinder can be solved by correcting the timing, not lessening the load - that just makes things loose, not a good thing in my opinion.

The other idea, that of bending the spring, has more merit, although I consider it a band-aid instead of a cure. Simply bend the finger that rests on the bolt fingers to lessen the curvature in that (bolt spring) finger only. This will be much more effective, consistent and longer lasting than loosening the screw. However, it will be very difficult to bend the spring the exact amount needed to achieve both a load reduction and still leave the spring fully functional. You need to do this in small increments, which will involve many assembly/disassembly cycles, and it will be difficult to see the effects of any one effort. Good luck.

 

[Leon DeGamme]

Sounds like you recommend that I dont mess with it. I guess if it still works, then I should just leave it alone.

 

[Misfire99]

Remember the first rule of gunsmithing. Don't fix it if it ain't broke.

 

[FSCJedi]

mykeal, thanks for the elongated explanation! I didn't think I'd been doing anything wrong. haha