View Full Version : Cylinder pin issues with 1860 Army

February 25, 2011, 06:02 PM
So today I finally got out and shot my ASM 1860 Army for real. That is with balls, not blanks like I usually do. Afterwards when I got back and started disassembling it for cleaning it was unusually hard to get the cylinder off. It became immediately apparent that the cylinder pin had some noticeable play and was "loose" (not sure on the right word). I don't see a way to tighten it back up. So..

1) How does a cylinder pin get loose? and...

2) How do I fix it?

For those of you who want to know: I was shooting ~35 gr. of Goex 3Fg blackpowder topped by a Crisco-greased .454" swaged ball. Then I sealed the chamber mouth with some crisco. This seemed to work quite well, a little messy but I didn't have any wads handy. I probably shot a total of 15-20 times.

This gun was given to me in poor condition (from apparent lack of cleaning). I have since cleaned it up nicely and got it back up to good working order. I don't know if it has ever fired balls as the previous owner used it a couple years doing a wild west show shooting only blanks. It then sat in a drawer for a number of years before being given to me. From the date code it was made in 1991.

Thanks for any help...

February 25, 2011, 07:44 PM
I could be wrong, but I'm betting your revolver has a brass frame. Loosening of the Arbor (base pin, or cylinder pin) is a common problem when you shoot a brass framed gun with as much powder as you were using. Recommendations are 20 grains or less in a brasser, but some use up to 25 (I wouldn't) and have no problems. If you have a steel framed gun, it could just be worn out or was abused before you got it. As you say, it was in poor condition when you got it. Fixing it (if possible) would probably cost more than replacing it with a newer replica.

February 25, 2011, 07:54 PM
It has the case colored steel frame. When I got it, nothing was loose. It was dirty as heck: rust and pitting were bad to severe in the barrel and inside the chambers. In fact it was overly tight due to all the gunk and rust. I believe this was the first time it was shot using balls. And now the arbor (as I guess is the correct term) is loose. It also has a larger cylinder-to-barrel gap now.

February 25, 2011, 08:02 PM
Somehow the frame got stretched. A bit unusual for a steel framed gun. Not sure if there is a good fix. You could take it to a smithy, but would probably cost as much as a new gun. Another thought is that it was slightly out of time, and the balls weren't hitting the forcing cone straight on. That can stretch and loosen a gun as well.

Bill Akins
February 25, 2011, 08:19 PM
There is a key pin that secures the arbor from moving that is located in the hammer channel where the curved portion of the hammer goes in the back of the frame. It is sometimes difficult to see because it is usually ground flush with the curved surface of the recoil shield/frame's hammer channel. This pin secures your arbor from moving. One way to remove it is to drill a small hole in this pin, thread it, insert a long but small diameter screw into it and using a automotive dent puller or something similar, apply rearward force to remove the pin. Then you should be able to rotate the arbor out.

This below quote is from one of the below links....
"Getting the pin out can be a major undertaking...that key pin removal can be a pain. If you do this, may think about using a small diameter allen head set screw as your new locking pin...if it ever comes up again, will be glad you did."

Here's another below quote from one of the below links.....
"Before you try any of the suggestions, how about you tighten the arbor, check to see if it is perpendicular to the frame, tap home the dowel pin, and see if that cures it. The dowel could have become loose, but still no wear or stretching of the threads, simply allows a couple thou turn of the arbor. Seat it, if that cures the problem, use a flat bottom drift to upset just enough metal to hold it secure."

Here's a couple of links for you to read that you may find helpful....


Hope this helps you.


Doc Hoy
February 26, 2011, 05:13 AM
If the overall geometry of the revolver is unchanged (or only minimally changed and still within good shootable specs.) and the only problem is that the arbor rotates slightly, you can tighten the arbor by tapping the frame with a center punch. I have done this on two or three frames with some success.

You are putting a small indentation with the punch in the frame and arbor where the arbor comes through the frame in the hammer channel. It should be done with the barrel and wedge in place so as to make sure that the arbor is correctly positioned. In some revolvers you can see the entire circular section of the base of the arbor in the hammer channel. When this is the case, it might not be a bad idea to dent both the top and the bottom of the arbor base. You have to have the hammer removed to do that.

This is not a great fix because all it does is tighten up the arbor on an otherwise near perfect frame. If there is damage to the threads on arbor or frame, it'll loosen up soon.

I have also tightened an arbor on an otherwise good frame by tapping the locating pin further into the frame. I was very surprised to find how far the pin would move into the frame. The pin did not bottom out until the surface of pin was about a sixteenth inch below the surface of the frame.

I recommend you start loading with a press. This will reduce the stresses placed on the frame to only those which occur when you actually shoot the pistol.

I hope others will verify this next comment. I believe (only because it seems right) that the stress placed on the frame would be less when shooting .451s rather than .454s. If the pistol performs adequately (as defined by you) with .451s you might want to move down. This might also lengthen the life of the pistol.

February 26, 2011, 07:16 PM
I will definitely try to tighten things up with a punch and a little hammer work. I am not very confident in drilling out the pin that connects into the hammer channel. Seems like a lot of hassle (then again with these guns it seems nothing comes easy). I appreciate the thoughts shared. I'll give it my best go. But with new 1860s being sold for less than $200 I don't feel comfortable turning this into an expensive and labor intensive project.

Doc, the only problem I have with going down to .451 balls is that the .454 balls aren't big enough. I have read here and elsewhere that when you ram the ball into the chamber you know you have a good fit when a small ring of lead is "carved" off. Well, as it is I am NOT getting this lead ring when I press the .454"s into the chamber. If I go down to .451 it may be a problem. Also you mentioned loading with a press. I assume you mean a device separate from the gun. I do not own a reloading press. Is that what you meant?

February 26, 2011, 11:48 PM
The lead ring won't form if the chambers have been chamfered, my 31 pocket had chamfered chambers and the ball is swaged and leaves no ring. Look for a relatively sharp edge(non cham) or beveled edge(chamfered).

Doc Hoy
February 27, 2011, 05:42 AM
You are correct in determing bullet size based upon your own observations. You have to be happy with what you shoot.

As regards the press, I am speaking of a device as you describe, which you can use to start and seat the ball on top of the powder/wad.

Cylinder comes out of the revolver and into the press. This permits two things.

1) In taking the cylinder out of the revolver, it becomes very natural to look into that chambers. I often find "stuff" in the chambers that I remove before loading.

2) All of the force required to load is applied to the press and not to the arbor or frame of the revolver.

For a long time, I did not use a press. I rested on the premise that the revolvers were designed to load with a lever, hence there should be no problem loading with a lever. But then, revolvers are designed to be fired too. Where do all these loose arbors come from? (That is a rhetorical question.)

Then I reasoned it out one day a coupla years ago. I talked to a physics professor who I am acquainted with and we reasoned (It is a fairly simple calculation that does not take a Physics professor) that the actual tension on the arbor during loading can be very high (I think I remember calculating as much as 350 pounds. That is like hanging a 327 engine block from the end of the arbor.) So I figured, "Why bother?"

My comment was not intended to start a discussion on the various presses, only to plant the seed. There are all kinds of presses out there but my thought is....don't go cheap. If you are handy you can make one.

February 27, 2011, 07:08 AM
tension on the arbor during loading can be very high (I think I remember calculating as much as 350 pounds. That is like hanging a 327 engine block from the end of the arbor
You're going to have to show me how you can generate 350 lbs of force on the end of the arbor.

February 27, 2011, 08:04 AM
Loose arbor, excessive barrel gap, time to sell it for parts and buy a new one. Unless you have a lot of time on your hands and nothing else to do it's hardly worth it to repair. It is a great learning experience and can be very satisfying to fix these old ones up but I decided I would rather be shooting.

February 27, 2011, 08:24 AM

If you decide you do not want to fix this old one up and decide to dispose of it, please send it to me. I would be happy to have it and restore it.

February 27, 2011, 08:30 AM
I already asked what he would take for it. He's not selling.

Doc Hoy
February 27, 2011, 02:53 PM
The mechanical advantage of the lever on an 1851 is about 7 to 8. I figure forty pounds (Might not be that high but I bet that is close) applied to the end of the lever times 7 to 8. All of the force is applied as tension on the end of the arbor. (Transferred through the pivoting screw which acts as the fulcrum, through the wedge to the arbor.)

280 to 320 pounds.

The geometry of the lever (Ratio of the distance between the fulcrum and the output and the distance between the fulcrum and the input) in an 1851 lever changes as the lever moves through its arc, so the mechanical advantage actually gets greater meaning that with a constant input force, output force is actually higher. But then the amount of force applied to seat the ball is not nearly as much as is required to start the ball into the chamber. So input force declines, therefore output may actually decline depending upon the rate of change of the mechanical advantage.

We also looked at it as if the fulcrum were considered to be the plunger meaning that the input force is the force you applied with your hand at the end of the lever and the output force is applied as tension on the screw, transeferred through barrel, wedge and thence to the arbor. (We thought this is not the case since the machine acts as a type two lever rather than a type one.

It is about the same either way.

We also looked at it as a rotating force since the force applied to the end of the lever actually changes direction along with the rotation of the lever. But this still left us with a substantially similar MA.

My recollection of 350 pounds was high if force applied is limited to 40 pounds. But lets say I was high both on the mechanical advantage, and high on the amound of pressure one applies with his hand during loading. Conservatively an MA of 6 and a force of 30 pounds = 180 pounds, way less than 350 pounds but still, would you want to pick up a person (Weighing 180 pounds) by suspending him or her at the end of your Colt arbor? (As though you were standing on a platform above the person holding your revolver frame in your hand with the barrel and cylinder removed. The revolver is pointing down toward the person in a swing. The person is sitting in a swing which is suspended by wire to the arbor of your revolver.

We actually started calculating the force on the barrel as the revolver is fired. Acceleration of a lead ball of known weight by the time it reaches the end of the barrel from zero to about 700 fps. But the most important factors (having to do with the resistance to acceleration imparted by the barrel/projectile interface) were unknown to us. We could not even get close on this.

February 27, 2011, 04:57 PM
I think something like this was on my Physics II exam in college......and I was very happy to take my "C+" and move on....:D

February 27, 2011, 08:20 PM
The more I look at it the more I am beginning to think that the loading process is the culprit for my problems. I have heard from numerous places here and elsewhere that ASM 1860s had sub-standard steel used for frames and parts that was softer than it should be. As Doc has stated there is quite a bit of force being applied to the loading ram when seating the ball & powder; I know I certainly was exerting a lot when I was loading.

I believe this not only loosened the arbor but also made it slightly deformed where the wedge slot is. The wedge itself is also deformed. The wedge was probably deformed from the stresses of shooting, but I am fairly convinced that it was NOT the shooting that messed up the arbor. The combination of soft steel and the forces described by Doc in the loading process are to blame.

I will likely have to replace the wedge and arbor -- for parts its probably going to be about $40-50. I may just replace the wedge and retire the gun from shooting balls and use it strictly for blank firing. I haven't made up my mind.

Doc Hoy
February 28, 2011, 05:06 AM
There are big differences in arbors from one manufacturer to the next. If the bore is pitted as you describe, this may not be a good shooter even if you get it to tighten up.

Hang it up and go buy three or four revolvers to overcome the grieving process.