Help with binding cylinder

[mtang45]

I have a new to me (approx 30 years old and unfired) CVA ARMI 1860 Army and it has an issue. It has one chamber that when rotating out of the firing position pretty consistently causes the cylinder to severely drag when cocking the hammer. The cylinder locks up and it literally changes the position of the cylinder vertically as it tries to rotate. If I back it up with my fingers, realign it and cock it while holding with my finders, it will continue to rotate until reaching that same chamber again. This may be why my dad never shot it. Looking at the cylinder/forcing cone gap it appears the cylinder is not aligned with the barrel. There is zero clearance at the top and very little clearance, but at least some clearance at the bottom when viewing from the side with a light source behind it. Definitely a triangle of light coming through the gap. It looks completely out of whack.

Anyone want to throw out some possibilities as to what is going on here? And, suggestions as to how to fix it?

Thanks

 

[Albroswift]

Hello. Following along.
Does the "Triangle of light" show at every bore position or only when you are at the sticky bore, more ligth at the other positions? Does the bolt drop into the cylinder notch before you wiggle the cylinder past the jam? It's possible the bolt is forcing the cylinder up before it drops into the notch, also 100 other things possible like a poorly machined cylinder face. I've collected several C&B revolvers over the last few months and parts don't always fit properly even when everything brand new.

 

[mtang45]

Hello. Following along.
Does the "Triangle of light" show at every bore position or only when you are at the sticky bore, more ligth at the other positions? Does the bolt drop into the cylinder notch before you wiggle the cylinder past the jam? It's possible the bolt is forcing the cylinder up before it drops into the notch, also 100 other things possible like a poorly machined cylinder face. I've collected several C&B revolvers over the last few months and parts don't always fit properly even when everything brand new.

It does change at each position. Some look nearly vertical and a few thousandths gap. Others its clearly touching at the top and minimal at the bottom. When it does jam and the hammer drops, it does miss the notch.

 

[Albroswift]

Another question, should have asked sooner, at half cock does the cylinder rotate freely by hand?
I'm leaning towards (possibly) timing of the bolt, tuning of the bolt. I'm far from an expert but sounds like the bolt is pushing up on the cylinder before it aligns with the notch in the cylinder? These are some pretty simple assemblies and there are some good videos out there if you want to take it on yourself. Also possibly the pawl is too short, bolt is too fat. Like I said I'm no expert but did recently fit a trigger. sear in a 1851 and a trigger/hammer/ bolt/pawl in a 1858 so learning. The 51 was just poorly fit from the factory and like your 60, old but unfired, and I wanted a nicer feel. The 58 started as a frame and barrel so all parts needed fitting/ timing. Nothing dropped in.
EDIT What I'm calling the "pawl" seems to be properly called the "Hand" in these revolvers.

 

[Jitterbug]

Looking at the cylinder/forcing cone gap it appears the cylinder is not aligned with the barrel. There is zero clearance at the top and very little clearance, but at least some clearance at the bottom when viewing from the side with a light source behind it. Definitely a triangle of light coming through the gap. It looks completely out of whack.

I’ll address the “triangle of light,” since it’s easiest for me to picture.

It sounds to me like the cylinder’s base pin hole is bored crooked(?).

 

[mtang45]

I’ll address the “triangle of light,” since it’s easiest for me to picture.

It sounds to me like the cylinder’s base pin hole is bored crooked(?).

I'll see if I can disassemble and take some pics.

 

[Albroswift]

I'll see if I can disassemble and take some pics.

Did you check for spin when half cocked?

 

[mtang45]

Did you check for spin when half cocked?

The cylinder spins freely at half cock.

 

[Albroswift]

The cylinder spins freely at half cock.

So sounds like a timing issue or bolt alignment with notch.

 

[mtang45]

I disassembled the revolver and I'm pretty sure the problem was caused by someone, my dad or the factory drove the wedge in way too tight. Does anyone have a recommended cylinder/barrel gap in thousandths?

However, now that this may be fixed I think I have discovered a secondary problem, shouldn't there be pins in the holes in the frame that match up with the holes in the barrel?

 

[Albroswift]

Yes, there should be pins. I think they should be pressed into the frame. Shouldn't be hard to find some drill rod the correct diameter if the pins can't be sourced.
Those wedges are pretty tight on low round count guns, but seat against the screw head and can't go in any further. Sometimes takes a brass punch and a solid support.
Forcing cone gap on my modern revolvers Are around 0.002, I've checked a few over the years worse one went 1-1/2 to 4 thou as the cylinder rotated (Taurus 44)
When a smith turns in the barrel and re-cuts it is around 0.001, at least on the few customs I am lucky enough to own. Don't know what the spec is on BP but probably around there. I can check a few tomorrow when I am back out in the shop.

The end of the base pin shaft the wedge goes through looks awfully rough, may just be the angle of the photo

 

[Albroswift]

Your going to have a good "Rescue" story when you are done. Cimarron has the pins (#23) for a couple bucks ea

 

[Albroswift]

Checked several black powder revolvers this morning, cylinder to forcing cone less then one thou to over 3 thou. Sometimes on the same cylinder! the 1851 was closest at 0.001" to 0.002" Also noticed some of them the forcing cone was not square to the face of the cylinder. I guess that is why the first thing they do on a custom is turn the barrel in and re-face the cylinder and cone.

Close enough for hand grenades and blackpowder!

 

[mtang45]

Checked several black powder revolvers this morning, cylinder to forcing cone less then one thou to over 3 thou. Sometimes on the same cylinder! the 1851 was closest at 0.001" to 0.002" Also noticed some of them the forcing cone was not square to the face of the cylinder. I guess that is why the first thing they do on a custom is turn the barrel in and re-face the cylinder and cone.

Close enough for hand grenades and blackpowder!

View attachment 45230

WOW!!! That is BEAUTIFUL!!!

 

[Albroswift]

A little flitz and elbow grease goes a long way.

 

[mtang45]

I'm learning all kinds of things from the interwebs. The two letter date code on this is AH and it means it was manufactured in 1981. Had no idea it was that old.