How to ream cylinders and to what size?

rodwha said:

I’ve long thought a Colt Pocket Police would make a nice little backpacking trail gun, but a lot of work would need to be done, including reaming and chamfering the chambers.

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I am slowly learning that reaming the cylinder chambers is not a requirement. I recommend pressing a .35 ball into a chamber, removing it and then seeing if the diameter is larger than the bore diameter rifling of your pistol. If it is then you are probably OK. Attention to other factors for the reliability of the pistol should come first. Duelist54's videos on reducing cap jams is excellent. I have done this to my navy and have not yet had a cap jam since (knock on wood).

I don't have the money for 45D to do a workup on my pistol but I am intrigued by the use of coil springs for the trigger and bolt.

fishmusic said:

I am slowly learning that reaming the cylinder chambers is not a requirement. I recommend pressing a .35 ball into a chamber, removing it and then seeing if the diameter is larger than the bore diameter rifling of your pistol. If it is then you are probably OK. Attention to other factors for the reliability of the pistol should come first. Duelist54's videos on reducing cap jams is excellent. I have done this to my navy and have not yet had a cap jam since (knock on wood).

I don't have the money for 45D to do a workup on my pistol but I am intrigued by the use of coil springs for the trigger and bolt.

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Yeah, the many issues with having a Colt are a reason for pause as well. Too bad nobody makes a Remington Police model. But I think a well working Colt would be really satisfying as well as looking so sharp, and I tend to prefer the older blocker design.

fishmusic said:

I understand that perhaps the cylinder diameters might be smaller than the bore diameter of the barrel and thus not engage the rifling fully. I would like to have the cylinders reamed on my Pietta Colt navy in .36 caliber. So, how is this done and is it something I can do at home? I bow to the experts on this and someday hope to achieve that status. I do not have reamers or gauge pins for measuring.

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fishmusic said:

I am slowly learning that reaming the cylinder chambers is not a requirement. I recommend pressing a .35 ball into a chamber, removing it and then seeing if the diameter is larger than the bore diameter rifling of your pistol. If it is then you are probably OK. Attention to other factors for the reliability of the pistol should come first. Duelist54's videos on reducing cap jams is excellent. I have done this to my navy and have not yet had a cap jam since (knock on wood).

I don't have the money for 45D to do a workup on my pistol but I am intrigued by the use of coil springs for the trigger and bolt.

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Stainless flat springs are faster acting and at least as reliable as wire coil . I make both.
It really depends on the application as I also have converted some rifles I've made from flat to coil and strut springs which are very reliable and especially smooth of operation.

fishmusic said:

I am slowly learning that reaming the cylinder chambers is not a requirement. I recommend pressing a .35 ball into a chamber, removing it and then seeing if the diameter is larger than the bore diameter rifling of your pistol. If it is then you are probably OK. Attention to other factors for the reliability of the pistol should come first. Duelist54's videos on reducing cap jams is excellent. I have done this to my navy and have not yet had a cap jam since (knock on wood).

I don't have the money for 45D to do a workup on my pistol but I am intrigued by the use of coil springs for the trigger and bolt.

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No, reaming it not required as some guns shoot lights out from the factory. When it really pays off is when wanting to shoot conicals along with balls or misalignment issues are in play.
Very often chamber mouths will be of different diameters or out of round from their mates in the cylinder and reaming will make them uniform.
Balls are more forgiving of slight misalignment and under groove diameter fit but they all will work when of at least groove diameter fit.
Odd numbered rifling can only be accurately measured by the use of a Tri-mic or Powelly gauge and a driven slug or Cerosafe cast. Pictured is a Powelly gauge I machined and stamped the formula for running the numbers on the face. Very accurate for odd numbered (3-5-7) rifling measuring.

Ed C. said:

I'm going through this right now. I have a Remington .44 cylinder that measures .446" and want to ream it out to .450/.451". I considered purchasing a chucking reamer. Cost-about $40 to $150+. You would need a good set up to be able to accurately position the reamer and keep it true. In the end I didn't want to take a chance on screwing up my cylinder so I sent it off to Charlie Hahn about 4 weeks ago and should get it back in the next few days. Cost? I don't know yet and don't much care. I am happy that the work is being done by a very experienced and respected gunsmith. I will post range test results when done.

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I got my cylinder back from Charlie Hahn and tested the gun out today. Considering there is still plenty of human element involved when I shoot off of my rest, a piece of rolled up carpet, I think the gun is shooting pretty good. Funny that my bench rest shooting is not much better than my off hand. Anyway, it did improve the groups I was getting and now have more trust in the gun.

Ed C. said:

I got my cylinder back from Charlie Hahn and tested the gun out today. Considering there is still plenty of human element involved when I shoot off of my rest, a piece of rolled up carpet, I think the gun is shooting pretty good. Funny that my bench rest shooting is not much better than my off hand. Anyway, it did improve the groups I was getting and now have more trust in the gun. View attachment 315264

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He does nice work. He can also accurize the 1861 Remington revolvers with Hoyt progressive rifled barrels…

BTW, for anyone considering doing this yourself, as Mike has noted, it’s not outside the reach of a home mechanic with a decent drill press. I did them myself for years and only stopped because Mr. Hahn said he would do them for such a low price. It’s been a while so I won’t guesstimate what that prices was but I promptly bundled up a half dozen cylinders and shipped them off to him. He did an excellent job.

If you just have one you need to ream you can source the necessary pin gauges (definitely need to know what size bore you’re dealing with) from Amazon or wherever very cheaply. Ditto for a chucking reamer and cutting oil. You may ask, “how do I determine the groove diameter?” Well, you can guesstimate as long as you know what the bore size is. Very seldom do the Italian makers cut grooves (or button rifle) deeper than a couple thousandths. So a .450” bore may have a groove diameter of .454”…
Here’s a link to the basic process with some other measuring tools and instructions. The author uses an adjustable reamer and I own one but I don’t trust it for work like this. I want the chambers straight and true and a drill press and chucking reamer can do this.

fishmusic said:

I understand that perhaps the cylinder diameters might be smaller than the bore diameter of the barrel and thus not engage the rifling fully. I would like to have the cylinders reamed on my Pietta Colt navy in .36 caliber. So, how is this done and is it something I can do at home? I bow to the experts on this and someday hope to achieve that status. I do not have reamers or gauge pins for measuring.

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This is the set up I use for open top cylinders. I prefer spud jigs that go through the barrel hole in the frame for close top revolvers.
The cylinder is held in a milling table between V blocks shimmed for protection. A 2 inch plug gauge that will just fit the mouth is mounted in the drill press quill and center is located by the x-y cross feed. When center is determined the spud gauge is removed and the chucking reamer installed on center in the drill press quill. The depth gauge in the last picture is dropped into each chamber before reaming for consistent depth of cut. The chucking reamer has a 45 degree taper on it's end.
This method makes the reaming as accurate as the chamber placement from the factory but not as accurate as spud reaming through the barrel hole in the frame of a close top revolver which squares it to the bore in the gun..
Usually all one wants reamed is the chamber mouths to a predetermined depth for seating of ball or bullet and or felt wad. Rebated cylinders are particularly sensitive to depth of cut for obvious reasons.

I used to ream down to the rebated portion of the cylinder on Colts. Not sure why exactly but it seemed to work well. Dave Clements used to line ream Ruger Ol Army’s to .4525” (same as stock from the factory) but the Ruger chambers are tapered from the factory at the rear end so he would remove the taper allowing for an additional 5 grains of powder capacity. Important for a hunting revolver. Not so much for general purpose guns. The Classicballistix cylinders were the same way…

Bad Karma said:

I used to ream down to the rebated portion of the cylinder on Colts. Not sure why exactly but it seemed to work well. Dave Clements used to line ream Ruger Ol Army’s to .4525” (same as stock from the factory) but the Ruger chambers are tapered from the factory at the rear end so he would remove the taper allowing for an additional 5 grains of powder capacity. Important for a hunting revolver. Not so much for general purpose guns. The Classicballistix cylinders were the same way…

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My new Walker chambers are larger at the mouth than down bore as well.

Bad Karma said:

BTW, for anyone considering doing this yourself, as Mike has noted, it’s not outside the reach of a home mechanic with a decent drill press. I did them myself for years and only stopped because Mr. Hahn said he would do them for such a low price. It’s been a while so I won’t guesstimate what that prices was but I promptly bundled up a half dozen cylinders and shipped them off to him. He did an excellent job.

If you just have one you need to ream you can source the necessary pin gauges (definitely need to know what size bore you’re dealing with) from Amazon or wherever very cheaply. Ditto for a chucking reamer and cutting oil. You may ask, “how do I determine the groove diameter?” Well, you can guesstimate as long as you know what the bore size is. Very seldom do the Italian makers cut grooves (or button rifle) deeper than a couple thousandths. So a .450” bore may have a groove diameter of .454”…
Here’s a link to the basic process with some other measuring tools and instructions. The author uses an adjustable reamer and I own one but I don’t trust it for work like this. I want the chambers straight and true and a drill press and chucking reamer can do this.

Click to expand...

Charlie Hahn's price came in at less than what a cheap chucking reamer, pin gauge and cutting oil would have cost me, not to mention not owning a drill press, lathe, or any type of milling machinery so it was a no brainer for me to send it off. A good job and peace of mind was well worth it.

Just a tip on measuring your chambers,
If you have a lathe, make a tapered plug gauge, smoke it and enter it into the chamber and gently rotate when it just touches then measure where it’s been ‘unsmoked’, repeat [with fresh smoking] for each chamber.
More accurate in practice than using ball gauges.
If you don’t have a lathe, taper a piece of hardwood in the drill press.

A couple of days ago received a cylinder reworked to use .451" sized bullets from .45 pistol molds.
Chambers are now .450" with a .452" x 3/8" deep step at the front. There is no perfect depth for this unless the cylinder is being set up for a specific powder charge and mold so I measured all the available mold cavities to arrive at a best ballpark number for the bullet weights I preferred. Looking forwards to seeing how this experiment works out.

M. De Land said:

My new Walker chambers are larger at the mouth than down bore as well.

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Wouldn’t 65 grains of 3f be more fun than 60?

Bad Karma said:

Wouldn’t 65 grains of 3f be more fun than 60?

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"Just 'cause it's fun doesn't mean it's a good idea!"

Ed C. said:

"Just 'cause it's fun doesn't mean it's a good idea!"

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Doesn’t mean it isn’t though either. Probably should try it once at least…

Bad Karma said:

Doesn’t mean it isn’t though either. Probably should try it once at least....

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Fire, smoke, 'n noise....that's a Walker.

Ed C. said:

Fire, smoke, 'n noise....that's a Walker.

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Oh yeah, big thunder… I had one once, years ago, enjoyed the smoke and noise but it was a tall order as a belt pistol so I traded it for something more practical. Darned if I can remember what that was…

fishmusic said:

I understand that perhaps the cylinder diameters might be smaller than the bore diameter of the barrel and thus not engage the rifling fully. I would like to have the cylinders reamed on my Pietta Colt navy in .36 caliber. So, how is this done and is it something I can do at home? I bow to the experts on this and someday hope to achieve that status. I do not have reamers or gauge pins for measuring.

Click to expand...

The cylinder is the big round thingie with 7 holes in it.
Chambers are the 6 holes where the powder and balls go.

Ed C. said:

Fire, smoke, 'n noise....that's a Walker.

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I sure am enjoying mine ! Should have had one years ago! Got more work to do on mine before it's up to speed on what I want plus I'm going to make a cross draw holster for it once I get to the leather shop up the road.
Had a pace maker installed a week ago and just got out of the hospital after clinically checking out last week on a glass job at a local equipment shop we service. My son did the CPR thing on me after dragging my butt out of the truck unto the shop floor.
Boy this getting old stuff is expensive and inconvenient ! He took a photo of me stretched out on the shop floor like a freshly landed carp with my upper cloths cut off and a gaggle of paramedics working me over. Don't remember a thing after blacking out until about 24 hours later. Boy, it don't take long to Die and it didn't hurt ! A humbling experience to be sure !
Yeshua decided it wasn't quite my time yet!