opening Uberti 1858 .44 chambers up

[thatoneguy82]

I have a Cimarron (Uberti) 1858 that needs the chambers opened up, the chambers mic out at .450, and the bore slugs out at .457. I'm having a hard time finding a reamer that size at a price I can live with, does anyone know of a place I could rent one?

 

[FishDFly]

I have a Cimarron (Uberti) 1858 that needs the chambers opened up, the chambers mic out at .450, and the bore slugs out at .457. I'm having a hard time finding a reamer that size at a price I can live with, does anyone know of a place I could rent one?

I am always trying to learn about revolvers, why do you want to open up the cylinder chambers by .007?

 

[Doug Attawy]

McMaster carr has them for @$35.

d-a

 

[Doug Attawy]

I have a Cimarron (Uberti) 1858 that needs the chambers opened up, the chambers mic out at .450, and the bore slugs out at .457. I'm having a hard time finding a reamer that size at a price I can live with, does anyone know of a place I could rent one?

I am always trying to learn about revolvers, why do you want to open up the cylinder chambers by .007?

The ball will never make a good seal (poor seal poor accuracy) if it is sized smaller than the barrel. Soft lead will obturate some but the gasses will blow by the lead in the process and could cause cutting of the ball and leading.

It's not just a issue in cap n ball revolvers, it's common in modern ones as well

d-a

 

[rodwha]

If the chambers are opened up to .457" what will you shoot through it? I looked for a .460" ball for my Ruger but didn't find one. Maybe opening them up to .454" would be better?

 

[swathdiver]

Get a .460, .461 mold.

Or sell it for parts on ebay and buy a brand new one with cash left over.

 

[FishDFly]

If the chambers are opened up to .457" what will you shoot through it? I looked for a .460" ball for my Ruger but didn't find one. Maybe opening them up to .454" would be better?

Again, attempted learned lessons, what is to be gained in going from .450 to .454, increase of .004.

Less lead will be shaved from the ball when it's seated. Seems to me that revolver manufacturers would have figured out needed tolerances after 100 years plus by now.

Ruger, going from .457 balls to .460 balls, gain of .003. Unless you are using a revolver loading stand you are going to increase the stress on the pistol loading lever parts which Ruger has none available.

See no practical reason to upsize ball diameter.

What am I missing?

 

[rodwha]

What has been noted by others when using large balls is that the increase in bearing surface increases the pressures slightly and also tends to increase the accuracy.

I've read several times of people going from the recommended .451" ball all the way up to a .457" ball and as the size went up the accuracy went up.

I've also seen how the little '63 Remington has grossly undersized chambers, and when the ball was increased it gave a tremendous increase in velocity.

Check this out:
http://poconoshooting.com/blackpowderballistics.html

 

[rodwha]

I will be having my Pietta '58's chambers opened up to .449" soon. Partly as I've read it increases the accuracy, but also so i can share projectiles with my ROA without stressing the loading lever assembly.

 

[swathdiver]

what is to be gained in going from .450 to .454, increase of .004.

See no practical reason to upsize ball diameter.

What am I missing?

This sixguns' chambers are grossly undersized. The ball will rattle around the barrel and not engage the rifling.

If he enlarges the chambers to .457 or .458 he'll obviously need a bigger ball. For balls to seat well and not creep, being .004 to .006 larger than chamber is good rule of thumb. So a .460-.461 would be in order. This is size for Pietta Shooter's Revolver I believe.

The relation between chamber and groove diameter should at least be the same but not more than .002 larger than groove diameter for best accuracy without undo pressure build up.

Hope I explained it right.

 

[FishDFly]

Sure wish we had some High Master shooters which could provide their insight to the subject.

 

[M. De Land]

What is needed it to get the mouths of the cylinders at or no more than .001 over the barrels groove diameter for best accuracy.
The reason smaller cylinder mouths work at all without gas cutting the ball is because of the forcing cone in the barrel root causing the ball to obturate and at least partially fill the grooves.
At the cylinder gap transition the powder directly behind the ball has not yet ignited and at this point is acting more like a wad until an inch or two up bore. Inertia and forcing cone resistance is working to expand the ball to fill the grooves unless the diameter is already sufficient to do so. Mike D.

 

[M. De Land]

I wonder why any ball near the bore diameter desired could not be orientated on the sprue and run through a simple bump up die to get the diameter desired. They wouldn't need to necessarily be cast to the needed diameter.
Balls are not round anyway when they are shaved to load or when inertia and the forcing cone gets done with them at muzzle exit.
I always orientate the sprue to 12 o'clock when loaded anyway.

 

[FishDFly]

Thank you, I was hoping you would respond.

Two questions, if the cylinder diameter is enlarged, is the cylinder stamped with the new ball diameter size?

New owner after modification thinks it's a stock Pietta 44 or what ever brand and it is not, needing larger balls. The pistol is now mis-represented when sold. Possible safety concern of either balls to small or too large.

Second you decide to enter "As Issue" matches. The pistol must be inspected prior to shooting. Range Master is wandering the line after inspection and notices you are shooting non-traditional size balls in that caliber and you are disqualified, cheating, the pistol is not longer "As Issue".

Thoughts on "As Issue" modifications and liability concerns.

 

[thatoneguy82]

It could just be an extra step to bump your round balls out, but I could anticipate issues loading as it might want to shift on you while trying to fumble it in there if you load with the cyl in the frame.

Thanks all for the leads on reamers, I'll dig into them tonight and source something. I have found a larger reamer that I am seeing what a local tool shop would charge to grind to dimension with the addition of a lead thats the original diameter of the chamber so it is sure to go in straight.

 

[thatoneguy82]

I beleive it is the bore size that is being represented and not the chamber dimension. Since there is a great deal of variability between manufacturers over roughly half a century it is quite likely that there is a +/- factor of at least .005 between different models. I had a Pietta 1851 Navy made in 1992 with a .366 bore diameter and bought a new Pietta cylinder that came in at .370. It seems that an individual interested in Cap&Ball is going to have to size for their individual gun as opposed to putting too much faith in that two decimal place number that is stamped on the side.

 

[M. De Land]

None of the chamber mouths in the same cylinder will be identical from a manufacturer.
They are usually gang reamed and each reamer has a wear tolerance deemed except-able.
I always check and record all chamber mouths in my revolvers and will usually ream them all to the largest diameter that will make a clean cut full circle.
I have also successfully opened them up with emery paper on a split reamer.
One needs a set of plug gauges to do this correctly or a split hardened ball gauge from which micrometer measurements can be taken.
Also one will occasionally find chambers out of round as well as having varied diameters from others in the same cylinder.
If I can get them withing a few tenths of each other and round I believe they are as good as they can be made to be. One mans opinion.

 

[M. De Land]

I don't feel it is necessary because all one is doing is making all the chambers as identical as possible and they are not so designated from the factory.
Ball fit will dictate diameter required anyway.
As with anything it is possible to over do it but if you keep the chamber diameters to not more than .001 over barrel groove no safety issues with pressure will occur. Mike D.

 

[M. De Land]

Here are the tools used to open up and line bore cylinders.

one inch mic, hardened steel plug gauge,split ball gauge,line bore alignment sleeve and the reamer that fit into it and a split pin for holding the emery paper to sand out a chamber mouth diameter.
Mike D.

 

[M. De Land]

I could be mistaken but I never thought "as issue" meant they could not be tuned but rather that no parts could be replaced with after market enhancements.
Obviously this does not mean a broken part cannot be replaced with a factory replacement. Mike D.