Another 1851 Navy Problem

[NCWanderer]

Got a small problem with my new '51 Pietta Navy, or maybe its not a problem, but it's got my curiosity up. At half cock I noticed the cylinder won't spin freely but turns easy enough by hand. After closer examination I noticed that when at half or full cock it seems that the hand spring pushes the cylinder against the forcing cone not allowing the cylinder to spin freely when at half cock. When the hammer is down the cylinder is held snugly against the forcing cone. BTW when I manually force the cylinder back it appears that there is .008"-.009" space between the cylinder and the forcing cone. Is all this normal?
Hope you can make some sense of this.....my writing abilities are not good.

 

[MCgunner]

Don't happen with MY Pietta 51. If the barrel wedge isn't properly fitted and installed, it can cause such binding of the cylinder. The wedge should install just passed where the spring catch grabs onto the top of the slot. You might have driven it in too far. It has a taper.

That's about the only thing that comes to mind. I just got through fitting a wedge to another barrel. It's a little on the loose side, but works fine. Before fitting, if installed, the forcing cone gap, or lack there off, would not allow the cylinder to rotate at all. I had to take a minuscule amount off the wedge on the front side with a flat file. Works fine, now. This was on a 7" barrel I got off Gunbroker. The 5.5" barrel it came with was fitted perfectly.

I'm no gunsmith, just something I taught myself about these guns lately.

 

[denster]

The cylinder being pushed against the barrel is exactly the way it is supposed to be. The design does not have a gas ring to hold the cylinder against the recoil shield. A gap when you hold the cylinder to the rear of .006 or a little more is about right.
Wedge fitting is another matter entirely. It should never be used to adjust the barrel cylinder gap.

 

[Old Fuff]

At half cock I noticed the cylinder won't spin freely but turns easy enough by hand.

When at half-cock the cylinder should rotate freely in a clockwise direction, but not counter-clockwise.

my writing abilities are not good.

Seem fine to me.

Remember that your 1851 revolver is an exact reproduction of one made 150 years ago, and they don't always work the same way modern ones do. The wide cylinder gap was necessary, as well as other preceived looseness because without it black powder fouling would eventually cause the gun to jam.

 

[MCgunner]

Wedge fitting is another matter entirely. It should never be used to adjust the barrel cylinder gap.

True, but I wasn't saying that, only that an ill fitted wedge will cause the cylinder to bind.

 

[denster]

MCgunner: I wasn't directing that towards your post, just addressing the common misconception that you adjust the gap with the wedge.

 

[rcflint]

The wedge, should be set at the same position each time the gun is assembled, which will make the cylinder gap, whatever it is, the same each time. The hammer protrusion in a cap & ball is set to fire a cap with the cylinder against the forcing cone, that way the firing is more positive, and the cylinder gap occurs under the recoil of the cylinder against the breech. About .006 to .008 is nominal for a cap & ball. Whether the cylinder will spin freely depends upon the strength of the hand spring and the friction of the arbor to cylinder bore. The cap & ball cylinder won't spin as freely as a cartridge revolver which has a gas ring or bushing holding the cylinder gap open.

 

[NCWanderer]

Thanks fellows

I knew I could depend on you folks to set me straight. It seem my concerns were unwarranted. I just field stripped it again. The cylinder spins freely on the arbor when not engaged with the hand. So the hand spring is the only thing keeping it from spinning when fully assembled. This Colt is somewhat of a new learning experience for me since my only other BP revolver is a Remy. Which BTW works fine. I knew I could depend on you folks to set me straight.

 

[arcticap]

MCgunner: I wasn't directing that towards your post, just addressing the common misconception that you adjust the gap with the wedge.

Since the position of the barrel is affected by the depth of the wedge, then the depth of the wedge can affect the cylinder gap.
From what I understand, the depth of the wedge places more or less upward pressure and torque on the arbor which can flex it and cause it to move upward and inward. Therefore the gap can be decreased as the wedge is pushed farther in.
So then the wedge should be backed out in order to increase the cylinder gap because not doing so can cause cylinder binding.
As described, the way that the wedge moves in and out does seem to be an integral part of the system for adjusting the cylinder gap. Even if that's only in fractional amounts, if that's how the wedge functions as the guns come from the factory then moving the wedge in and out to adjust the cylinder gap isn't a common misconception.

 

[denster]

Actually what is supposed to happen, with a constant diameter arbor like Pietta uses, is the arbor should bottom out in the barrel at the same time the barrel lug meets the frame. The wedge if it is properly designed, which Pietta's is not should be used only to lock the barrel onto the frame. Most of the time Pietta gets the arbor length correct. When they do not and the arbor is short the barrel can be forced further onto the arbor putting undue stress on parts and closing up the barrel/cylinder gap. The misconception is that this is the way it is supposed to be. It is not it is a flaw in the construction and should be corrected.
Now we get to the wedge. Pietta has totaly screwed this up. Pietta wedges are tapered on the side facing the muzzle for the entire length. On the side facing the cylinder they are sometimes tapered the entire length and sometimes only the last quarter inch is tapered. The end of the wedge slot in the arbor, towards the muzzle is at 90 degrees to the outside diameter. With this arrangement there is unequal pressure on both sides of the barrel slot and the wedge can only contact the top inboard corner of the arbor slot.
A properly designed wedge and arbor slot, like Uberti and Colt use/d is like this. The wedge on the edge towards the cylinder is exactly parralel to the centerline of the wedge ie: no taper. On the edge towards the muzzle it is tapered to correspond to a like taper in the end of the arbor slot, as I recall the fall is about .008 in .100. With this the wedge exerts equal pressure on both sides of the barrel and makes contact with the arbor across its entire diameter. It only needs finger pressure to push it into contact and a light tap to solidly lock it in place and a light tap to release it.
Wedges have been used to lock things in place since ancient times and it just befuddles me that Pietta could screw something so simple up. It's fixable and not really hard but why should you have to.
The misconception that this is the way it is supposed to be just because it came that way from the factory is just, well, wrong.
Once again the wedge is only to hold the barrel on, nothing else. If it is a Pietta, fix it. If the arbor is too short, fix it. If, once those are fixed, the b/c gap is too close take a small amount off the back of the barrel. If it is too wide take a small amount off the face of the barrel lug where it meets the frame. That is the correct way to do it.

 

[pohill]

You can't overlook the wedge screw. Colt intended it to act as a depth set for the wedge, to allow the wedge to enter the arbor slot enough to hold the barrel/frame connection tight but not so far that it would cause the cylinder to bind. Of course, this was on handfitted original Colts, not Italian repros that aren't hand fitted or machined as closely as the originals. I have an 1851 .36 made in 1862 and the wedge still does was it was intended to do - keep everything tight but not too tight. The wedge screw has an oversized head that actually contacts the wedge where it should.
Check out this patent.
http://www.google.com/patents?id=bNI_AAAAEBAJ&printsec=claims&zoom=4#v=onepage&q&f=true
Skip over the diagrams and go to the first page of the patent description, last paragraph in the second column that starts: "Figs.1, 3,4, 5 represent the key." It describes the intent of the wedge (key).

Then there's this patent paragraph:

 

[Skinny 1950]

I am glad I ordered the Uberti...........

 

[TheRodDoc]

Denster is exactly right. And that piece from the patent is talking about what he described. Nothing about the wedge screw.

And the wedge key screw is only to keep the key from falling out on the ground when removing the barrel. Not for any kind of adjustment.

 

[arcticap]

Actually Uberti Colts are more well known for having arbors that are too short.

 

[pohill]

And the wedge key screw is only to keep the key from falling out on the ground when removing the barrel. Not for any kind of adjustment.

Really? And you read the patent? The part that reads: "the head of this screw, overlapping the end of the mortise, receives the wedge and checks it. By turning this screw, the force of the wedge may be tempered." Hmmm....

And that piece from the patent is talking about what he described.

Again...really? You mean the part where he said

Once again the wedge is only to hold the barrel on, nothing else.

What about the part of the patent that reads: "...the key can be driven further in, and the proper distance for the readjustment of those parts be maintained, whilst the essential rigidity of structure is secured..."
Sounds like the wedge was meant to do more than just hold the barrel on.

 

[madcratebuilder]

In regards to Colts patient and the fitting of the wedge please check the date on the patient. August 29th, 1839. I believe this patient is for the Paterson model with the loading lever. The first Paterson patient was February 25, 1836. The design of the Colt revolver was continually evolving and changes are not always reflected with a new patient. I don't recall seeing a Paterson wedge with a wedge spring, the first wedge springs I believe are on the Walker. At this point the screw was used to retain the wedge to the body of the barrel when disassembled and no longer used to set the wedge depth. Just my .02.

 

[denster]

Several points.
Pohill your post with the patent was incomplete it doesn't include the part about the screw limiting travel of the wedge.
Also the patent clearly states that if the barrel needs to be set back first metal needs to be removed from the end of the arbor or the arbor hole deepened. That is the adjustment. Then the wedge can be moved farther in to hold the barrel in place. Actually you also need to remove metal from the barrel lug where it meets the frame. Not mentioned but the author of the patent probably overlooked this as just being common sense.

Yes Uberti Arbors are always short. They address the matter in a different way, which works well as long as the wedge isn't driven in too far and ruins the fit. Uberti arbors are tapered along the part that goes into the arbor hole under the barrel. The arbor hole is also tapered to receive it. At the point where the barrel lug has met the frame the diameter of the arbor is the same as the max diameter of the arbor hole to keep it from going on any further.
The wedge is an incline plane, a powerful tool, and driving it in hard can ruin this nice fit and also stick the two tapers together and make it hard to take the gun apart. I always lengthen Uberti arbors just for this reason, even though if the gun is properly handled it is unneccesary.

 

[Old Fuff]

The purpose of patents is sometimes misunderstood, especially during the 19th century. On one hand a inventor would seek protection for the unique features of his invention, but on the other hand would also cover any and all additional things that he might include to prevent there use by others.

Patents once issued were not changed, except by obtaining later ones. Colt clearly understood that potential competitors would read the fine print in his patents, looking for loopholes that would allow them to cut out a piece of the profitable revolver business. It may be said that Colt didn’t provide many (if any) such opportunities for others. But by the same token, Colt’s revolvers were not always absolutely 100% faithful to the patents, as they were written. If they had been, Colt couldn't have introduced changes as experience over time dictated. When such changes were substantial and unique, Colt would obtain an additional patent to cover them.

Also there were some features in Colt revolvers that were not patented because they were not unique, and commonly used by others in the industry.

 

[pohill]

The first patent that I linked to was for the Paterson. As I said, the original intent of the wedge screw was to set the depth of the wedge. It's all right there in the patent. To say that the patent refers to one type of gun with a wedge, and not others that followed, is like saying that the 2nd Amendment applies only to the types of guns available when it was written. And remember, the first gun (Paterson) and one of the last guns (1862 Pocket Police .36) that Colt designed did not have a spring on the wedge, but they did have the wedge screw. Why?

As far as the second patent being incomplete - if you read the last section of what I posted (it starts with "In the event of any abrasion of the end of the cylinder..." - I see that as meaning that as parts wear (end of cylinder, barrel (forcing cone), deepening of cavity, end of arbor), and adjustments have to be made, you can adjust the wedge to keep things tight but not too tight, which, again, refers back to the wedge screw as the depth set.

 

[denster]

You are misreading what you posted. The patent states that for whatever reason the barrel needs set back you can file some off the end of the arbor or deepen the hole and then the wedge can go in further to bring the parts together. Again the wedge is only for holding the barrel on the frame.
As regards the change in design of the wedge with the 1862 where Colt deleted the spring. The tip of the wedge is now closed to allow the screw head to keep it in the gun, the back of the wedge is now open with nothing for the screw head to contact to limit depth of seating. Actually this was a major improvement and got rid of that annoying spring. I make all replacement wedges this way regardless of model just because it is a better idea. It does reinforce what Madcratebuilder said about Colt's design being an evolving process.
While all of this makes for an interesting discussion it has little to do with what needs to be done to these revolvers to make them reliable and durable for the long term.

 

[pohill]

Very very doubtful that I am misreading anything. Very doubtful. Try rereading it yourself. It reads..."In the event of any abrasion of the end of the cylinder, or of the barrel, by deepening the cavity (the hole in the frame where the base pin or arbor fits and should bottom out - if the cavity deepens the arbor will not bottom out), or filing the end of the base pin (again, if the hole deepens or the pin becomes shorter, adjustments must be made) the key can be driven further in, and the proper distance for the readjustment of those parts can be maintained." What am I missing? That, clearly and simply, is talking about parts wearing, and what to do about it. Reread it aloud if you have to.

 

[denster]

Quote Pohill: Very very doubtful that I am misreading anything. Very doubtful. Try rereading it yourself. It reads..."In the event of any abrasion of the end of the cylinder, or of the barrel, by deepening the cavity (the hole in the frame where the base pin or arbor fits and should bottom out - if the cavity deepens the arbor will not bottom out), or filing the end of the base pin (again, if the hole deepens or the pin becomes shorter, adjustments must be made) the key can be driven further in, and the proper distance for the readjustment of those parts can be maintained." What am I missing? That, clearly and simply, is talking about parts wearing, and what to do about it. Reread it aloud if you have to. End Quote

Maybe you should follow your own advise. Think about this for a minute. "In the event of any abrasion of the cylinder or the barrel". In either of these cases the barrel is going to need to be set back.
Solution: "by deepening the cavity" that is one part you haven't shortened the arbor so the cavity needs deepened so the barrel can move back. "or" this generally means as an alternative to but not both. "Filing the end of the base pin" now you would not need to deepen the hole as you have accomplished the same thing by making the arbor pin shorter and the barrel can move back.
In either case the adjustment was made to the arbor hole, or not both, the length of the arbor pin. The wedge now will go in further, obviously, to hold the parts together and accomodate the adjustments that were otherwise made not make any adjustments.
Items enclosed in quotes are from the patent the rest are my comments.
I don't know how I can make it any clearer.

 

[TheRodDoc]

That means more or less that the wedge key automatically readjusts the fit each time it is pushed in. If there was some wear on the arbor end or hole depth then the next time the wedge is pushed in it pulls the barrel back the amount of the wear till the arbor bottoms in hole again. This can happen till the cyl. gap gets to tight. Then the gun must be worked on. The arbor lengthened or hole filled some. Then the process starts all over again.

 

[pohill]

Well, you read it the way you want - I see it like this (I've added two ORs for clarity):
..."In the event of any abrasion of the end of the cylinder, OR the barrel, OR (added word) by deepening the cavity OR (added word) filing the end of the base pin...the key can be driven further in, and the proper distance for the readjustment of those parts can be maintained."

You say that deepening the cavity is a solution - I say it means wear at the bottom of the hole caused by the arbor bottoming out.
And I also say that "filing the end of the base pin" refers to wearing of the tip of the arbor so it doesn't bottom out, which is the same as the hole deepening.
My interpretation is based on the idea that the gun was fitted properly when it was new (in the 1850s, for example) but the parts wore as time went by, and driving in the wedge and adjusting it with the wedge screw was the solution. You sound like you're starting with a defective gun, in which case I will agree with you if it's an Italian repro, but not an original.

RodDoc - I just read your last post and that's all I'm saying - the wedge compensates for any wear to the gun's connecting parts, and the wedge screw tempers the force of the wedge.

 

[denster]

RodDoc. No that is not what is meant. The end of the arbor and the bottom of the arbor hole do not wear any appreciable amount. Even if they did you couldn't use the wedge to adjust because you have the meeting of the barrel lug with the frame to contend with. You know that part that has the two locator pins on the bottom of the frame. It would kind of get in the way.
Pohill. Go ahead and re-write the patent anyway you want. You're still wrong.