Honing C&B Revolver Chambers

I purchased an older Pietta 1862 Police in 36 caliber last year from an estate. The main spring is probably 800 pounds and I can easily deal with that issue. My problem is the inside surface of the chambers. To say there was a manufacturing problem would be an understatement. I have tried "polishing" them with Brownells lapping compound and a brass cleaning brush but these need a more aggressive approach.

Do you think a Flex-Hone would cure this mess or is an even more aggressive approach needed? I would love to hear some suggestions as to cleaning this mess up. I am not worried about going slightly oversize after smoothing.

Bear in mind that this is a CLOSED chamber on a Cap & Ball revolver so I can't push all the way through with any tool.

Other than a new cylinder, any suggestions? DougGuy??

Attachment 280810 Attachment 280811

Ouch! I don't have any answers for you - but I look forward to hearing from those that do.

Sent from my Pixel 5 using Tapatalk

I had one like that made in the 70’s All the black powder cylinders are under size any way usally .006 so honing would be a good thing.

See what size it is now, and if less than 3/8" then I'd use a .375 chucking reamer on it to make it the right size and fix the finish in one shot. Then finish with a fine ball hone. Or at least that's what I did to my '51 Navy and it improved the accuracy considerably.

I wouldn't use a chucking reamer at all, nothing to keep the reamer on center. To do that right, I would use a reamer with a shortened pilot bushing then hone it with the Sunnen hone. A ball hone doesn't do anything to remove any ridges or high lows, it polishes whatever it comes in contact with but it won't make the charge holes any more cylindrical. If I could get away with just using the Sunnen hone, I would do that but sight unseen I can't tell if it could be done this way.

If you want to send the cylinder, I can pin it and see how much needs to come out of it and see if I have a reamer close to that without going oversize, and see if I can shorten the pilot on it so it will reach down into the hole far enough.

Having to modify reamers for a one time job is not really very cost effective, but sometimes you gotta do what you gotta do to make things work. I did 3 reamers for the ROA cylinders, and they come out at .453" after reaming and honing and re-chamfering, but they're not cheap to do. They shoot REALLY good afterwards though so it's a buy once cry once type of job.

Also it's not like a metallic cartridge cylinder, it doesn't have to be the exact diameter underneath where the ball seats, it can be smaller once below where the ball is seated is smooth and corrected, but each charge hole does need to be consistent in volume.

The normal reamer works fine. You do need to make sure it's held straight and the hole indicated, but once you do that it's not a problem. And since the chambers are (or should be) tapered, a pilot doesn't work. You are correct though that it only needs to be cut somewhat deeper than where the ball or bullet stops. You definitely do not want to go all the way to the bottom.
I made a neat fixture for the mill to do this with my Navy cylinder, but don't have one for the pocket cylinders. You do not want to try just holding it in a vise, too easy for it to move.

First thing I would need to know is the groove dimension in barrel. Then pin/mic cylinder bores and then make decisions from there. I also see a lot of chamfering on face, that one creates another less filling taste great battle when you get there.

My "trick" with the ROA cylinders is using a dull worn reamer first, it cuts only a tiny bit down to the first .500" which the dull flutes serve to guide the reamer in the cut it just made without really cutting more on the sides, and by the time it is cutting a little more meat, there is enough of a fresh cut behind the leading edge to serve as a self centering pilot and it works pretty well. This first pass only parallels the charge hole so the pilot bushing on the next reamer will work as it is supposed to. Then I switch to a piloted reamer that I have modified the pilot bushing to just a button, and that takes the final cut on down until the button bottoms out, uniforming each chamber, the third reamer is a No.4 tapered reamer that I cut off and ground a live pilot shank on, and I use a pilot bushing to center it and this one cuts the very slight chamfer that the factory cut on them for loading a ball. This allows you to start a .456" ball and swage it down to .453" once seated.

These are all hand reamers, cylinder held in a soft vise and reamers turned by hand with a handle. A mill could do all but the chamfer in one pass, I just don't have a mill and don't need one to service cylinder throats and barrels.

Ye Gods! How did that cylinder ever get out of the factory? Oh, it's Pietta, never mind.

Being a cap-and-roundball cylinder, only the first 1/2 diameter really needs to be cleaned up. Just deep enough to minimize tearing of the ball as it's seated, So I like DougGuy's approach. Is a Pietta worth it? Only you can answer that question.

Quote:

---

Originally Posted by DougGuy

My "trick" with the ROA cylinders is using a dull worn reamer first, it cuts only a tiny bit down to the first .500" which the dull flutes serve to guide the reamer in the cut it just made without really cutting more on the sides, and by the time it is cutting a little more meat, there is enough of a fresh cut behind the leading edge to serve as a self centering pilot and it works pretty well. This first pass only parallels the charge hole so the pilot bushing on the next reamer will work as it is supposed to. Then I switch to a piloted reamer that I have modified the pilot bushing to just a button, and that takes the final cut on down until the button bottoms out, uniforming each chamber, the third reamer is a No.4 tapered reamer that I cut off and ground a live pilot shank on, and I use a pilot bushing to center it and this one cuts the very slight chamfer that the factory cut on them for loading a ball. This allows you to start a .456" ball and swage it down to .453" once seated.

These are all hand reamers, cylinder held in a soft vise and reamers turned by hand with a handle. A mill could do all but the chamfer in one pass, I just don't have a mill and don't need one to service cylinder throats and barrels.

---

Ah, I see where you're coming from. That works too! We adapt our techniques to the tools we have, many ways to get to the same ends.

First things first
If you gonna attack this may as well make sure the gun is dimensioned right
Slug the bore and measure your cylinder properly before you start - some of these repros have some pretty crazy measurements

I did an older 1860 army and a walker both with stupid deep rifling and undersize chambers -- groove to groove was .460 and chamber .452
So I made a reamer to cut .462 and reamed both cylinders by hand just deep enough to allow a ball with decent clearance (didnt need or want more powder capacity in either gun) - got a Pedersoli mold in .464 (which off the shelf availability kinda tells me this is not an uncommon problem) - both guns now give good accuracy with full chamber powder loads and a couple greased egg carton wads.

Made the reamer from a grade 5 HT bolt (the one with three bars on the head = carbon steel easy to heat treat - grade 8 bolts - six bars - are alloy steel no fun there at all) I put a short tapered lead on it and chose to turn it by hand with a TEE tap wrench (envisaged less trouble doing it by hand) both those cylinders cut like butter. Very pleased with the result on the range.

I would make sure of the measurements here first - you might end up needing an oversized mold to get ball size / cylinder / bore matching --the difference in the two guns I did was pretty dramatic - well worth the effort.

Just doing one presents a problem. Reaming is the best way but you need some way to keep the reamer lined up. A drill press will work but you need a way to make sure the reamer is in line with the bore. I had a job a while back that involved re-chambering sever Ruger cylinders so I made up a fixture to keep everything lined up.

Attachment 280868

^^^How a pro does it ^^^

Wooden dowel with emory cloth wrapped around it with plenty of oil.

Hard to tell from the pics but it looks fairly deep.

As stated the cylinders tend to be on the small side. If it .003 deep you will have to open the cylinder .006" if you want full clean up. If you do that you will need to open up the other five.

It looks awful but is it creating any real issues? If it was mine I would test it to see what issues it is creating. If no issues not doing anything is an option. If it creates issues I would make them all the same.

A company I used to work for did a lot of roller reaming/burnishing That would be the ideal but you would have to have a buddie working at a place that does it since it's not common and tooling is very specialized and not cheap.

https://www.youtube.com/watch?v=eUb6ZAes8FQ

Quote:

---

Originally Posted by John Taylor

Just doing one presents a problem. Reaming is the best way but you need some way to keep the reamer lined up. A drill press will work but you need a way to make sure the reamer is in line with the bore. I had a job a while back that involved re-chambering sever Ruger cylinders so I made up a fixture to keep everything lined up.

Attachment 280868

---

Using your Bridgeport makes the job a lot easier.

If you use a .375" reamer, you will need a bigger round ball. Fortunately Lee makes (or did) a .380" RB mold.

Robert

Quote:

---

Originally Posted by John Taylor

Just doing one presents a problem. Reaming is the best way but you need some way to keep the reamer lined up. A drill press will work but you need a way to make sure the reamer is in line with the bore. I had a job a while back that involved re-chambering sever Ruger cylinders so I made up a fixture to keep everything lined up.

Attachment 280868

---

Now THIS is why I spend so much time on the sidelines here!!!

Sent from my Pixel 5 using Tapatalk

Quote:

---

Originally Posted by M-Tecs

Using your Bridgeport makes the job a lot easier.

---

hmmm .........I chose to ream by hand because it was easier and less likely to cause me grief ....used the mill to cut the reamer flutes ... maybe I got lucky?
reaming in the mill maybe makes a better job (I dont believe the target would prove that) but your setup needs to be absolutely 100% precise or its likely worse.

One problem with reaming by hand, unless you have a pilot, it is easy to bellmouth the start. That pic with the collet holder holding the cylinder is by far the most accurate method after indicating. This is assuming the factory located the bores an accurate degree of separation, otherwise you indicate each bore as you move to the next bore to be reamed. If you are brave enough you could actually clean it up with a mini boring bar.

Making sure the cylinder is lined up with the bore I have made up dummy barrels for the Remington and used it as a guide for the reamer. It's a little hard to do with the open top Colt.

Quote:

---

Originally Posted by shortlegs

Wooden dowel with emory cloth wrapped around it with plenty of oil.

---

I've bought a few parts guns/ gun parts in a box and made some put together revolvers..all Italian pieces..and yeah..paper on a dowel has cleaned up years of abuse pretty easily..

Quote:

---

Originally Posted by John Taylor

Making sure the cylinder is lined up with the bore I have made up dummy barrels for the Remington and used it as a guide for the reamer. It's a little hard to do with the open top Colt.

---

The open top should be as fine as the Howell type 6 shot conversion cyls for the Remington pattern revolvers. Even though the chambers are slightly angled to allow 6 cartridges, many folks consider that particular setup to be excellent and with (usually) amazing accuracy (me included). You may can get away with a dummy barrel setup that has a threaded (nut maybe) section that would allow a bolt to be screwed against the front end of the arbor, after the wedge has been inserted, to align the barrel/cylinder with zero clearance.

Mike

It would be cheaper to get a new replacement cyl. But then the chambers are still under size. I have seen .005 to .007 under on the Italian repos

Doug how do you handle tapered chambers in cap and ball cylinders ?

I personally saw a current production Uberti percussion .44 New Model Army that had a slight non-visible taper (smaller towards the back) in the cylinder throats which defeated the use of the hand reamer guide attachment.

That cylinder currently has the guide piece wedged inside after a foolish attempt by yours truly to force it in further. Nothing I tried could get it out. Thankfully a new drop in replacement cylinder was handy.

I figure a .36 navy caliber 1858 New Model Navy cylinder would have plenty of wiggle room for reaming to bore size without much thinning of the cylinder walls but I would be hesitant to try because if it also has tapered chambers it won't work and the closest size to .36 cal cylinder reamers I see sold online are for cylinders that use .38 special/.357 cartridges (.357 bore) way too small.

I guess I would have to slug the bore and get a custom size reamer assuming the cylinder walls are not tapered.

I would love to be able to send it to someone who has the means and knowhow to do both the .44 and .36 percussion cylinders right.

Quote:

---

Originally Posted by John Taylor

Just doing one presents a problem. Reaming is the best way but you need some way to keep the reamer lined up. A drill press will work but you need a way to make sure the reamer is in line with the bore. I had a job a while back that involved re-chambering sever Ruger cylinders so I made up a fixture to keep everything lined up.

Attachment 280868

---

AND all three revolver owners are VERY happy and the 10x25mm Rugers drive nails like rifles!

Attachment 284481

Quote:

---

Originally Posted by grter

Doug how do you handle tapered chambers in cap and ball cylinders ?

I personally saw a current production Uberti percussion .44 New Model Army that had a slight non-visible taper (smaller towards the back) in the cylinder throats which defeated the use of the hand reamer guide attachment.

That cylinder currently has the guide piece wedged inside after a foolish attempt by yours truly to force it in further. Nothing I tried could get it out. Thankfully a new drop in replacement cylinder was handy.

I figure a .36 navy caliber 1858 New Model Navy cylinder would have plenty of wiggle room for reaming to bore size without much thinning of the cylinder walls but I would be hesitant to try because if it also has tapered chambers it won't work and the closest size to .36 cal cylinder reamers I see sold online are for cylinders that use .38 special/.357 cartridges (.357 bore) way too small.

I guess I would have to slug the bore and get a custom size reamer assuming the cylinder walls are not tapered.

I would love to be able to send it to someone who has the means and knowhow to do both the .44 and .36 percussion cylinders right.

---

Today I noticed a #7 taper pin reamer goes from .3297" to .422" over a length of 4.437". That should cover 36 caliber revolvers nicely. I am working on a Pietta 36 cal currently so ordered one of those reamers to give it a try. We'll see how that works out.