Can you suggest a correct ball diameter?

[Chill Wills]

Can you suggest a correct ball diameter?
I have my old (45 years old) Italian, brass frame, open top, Colt copy, 36 cal cap & ball revolver and want to get it going again. I have never cast for it and so need a mold of proper size.
I have a set of pin gauges, so I checked the cylinder mouths. All excepted 0.356" and two 0.357". I have not sluged the barrel but I will at some point.
My Ruger Old Army cylinders measure 0.451" and it is stated to use 0.457" balls, and that is what I do. They work well.
Using this as a guide, I could use a 0.365" ball in the 36 Colt. But I think people normally use 0.375", and I bought 0.375" in the past. I think?

I wonder what might be better?

[rodwha]

Those chambers tend to be larger though. A bit oversized is good but up to a point. Eventually it puts undo strain on the lever assembly.

I'm curious what your barrel slugs at. If those are too far apart it might be good to ream the chambers assuming there is meat between the chambers.

At this point I think 0.365" is enough. I wouldn't go beyond that.

[Battis]

I'd use .375" pure lead. I've never had to go smaller with a .36 cap and ball. Keep the loads low - brass takes a beating.
This is from a previous owner:

[54bore]

And to think i just melted down several brand new boxes of .375 Lead balls, most of them were new sealed boxes. I stil have a few boxes of .395 that will be added to the melting pot shortly

[rodwha]

I've read of people complaining about the strain and having things break with Pietta Remington NMA's with 0.446" chambers and using 0.457" balls. Pietta and most others state the 0.451" ball is what those smaller chambers need. Going too far over the chamber diameter isn't a good idea.

I had my Pietta chambers reamed to 0.449" and chamfered and I use 0.457" balls and 0.456" boolits without too much extra force needed, but that chamfer no doubt helps.

[mooman76]

.375 is what most use and that is what is most common. I have heard however some claim a .380 is actually more accurate but it is allot less common and moulds are harder to find. On your other revolver .454 is used allot. Most claim when you shave off a tiny little lead ring when loading, that's where it should be. I have no reason to disbelieve it.

[rodwha]

But what sized chambers are on your average .36 cal revolvers?

The Uberti Police model has .372" chambers. A big difference between that and what the OP measured.

[Chill Wills]

Thanks for the replies men. Reading this, I think there might be a range is size that works. I think getting a lead ring when seating the ball in the cylinder is good. Getting too much ring works the lever too much - that makes sense.
My next step is to drive a slug through the barrel/bore and see how it compares.

I'll be right back after I do that.

[pietro]

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For any C&B revolver, Best Practice indicates that the ball should be of a size (diameter) that shaves off a thin, but even, ring of lead as it's seated in the chamber mouth.



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[Chill Wills]

Right. If the cylinder does not shave a ring, the ball is too small. If the ring is not even all around, the ball becomes out of balance. Thin to one person may be thick to another.
I am just wondering if a guideline for, how much bigger, exists.

I fired up the Pb pot to cast a few soft slugs. I should know the barrel measurements soon.

[Chill Wills]

The barrel is 0.365 land and 0.375" groove. I'm good with that.
However, the cylinders are 0.356". That does not seem like that should be.
The entrance to the forcing cone is 0.390"

I know - BP bumps up Pb round balls. However, this still does not work well in my mind.

[pietro]

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Sometime, folks can overthink things.....................

Shoot it - if it isn't broken, don't "fix" it.


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[Battis]

The problem with relying on a shaved ring of lead is if the chamber mouth is chamfered (beveled). The ball will seat lower and might not shave lead (or not as much).
I'd start with .375" roundballs, which are usually on the small size. Most of my .36 revolvers use .380". Some of the older ones could use .390".

[rodwha]

The .31 cal Pietta Remington has such undersized chambers that velocity and accuracy suffer greatly, and compared to the Colt models they are pathetic. An oversized ball helps, but obturation only goes so far.

Again it seems the typical .36 cal revolvers have larger chambers than what the OP states. And much larger (on a scale) to where a .380 ball is often better such as with the Uberti Colt Police model.

The ball used generally is less than 0.010" over chamber. My ROA, which cals for a 0.457" ball has 0.453" chambers. The Uberti Remington's have 0.450" chambers and call for a 0.454" ball, and the Pietta version has 0.446" chambers and calls for a 0.451" ball, and those chambers are on the small size.

Again, what is the typical chamber size of these .36 cal revolvers? Measure yours and see what you get compared to the ball you use. Or even try using 0.390" balls and see what you feel. I loaded a cylinder of 0.490" balls in my Ruger once as I forgot to grab some and it took quite a bit of effort which I wasn't nearly as worried with since the Ruger isn't made with softer steel. I wouldn't do it again unless I had to for some reason. I wouldn't do that with my Pietta even if it had 0.453" chambers that were chamfered.

*EDIT*

Those .44/.45 cal guns all have a ~.452" bore. Ruger made theirs correctly. And the chamber sizes listed for the repros are not the match grade guns you spend a good bit more on.

[rodwha]

I'd still look at opening up those chambers. They are too small compared to the bore and using a 0.375" ball or larger is certainly adding undo stress to the lever assembly.

If not that you'd potentially want to bring the bore down to ~.357" by lining it. Unless you don't care enough.

[dondiego]

Don't they make replacement cylinders? Boring the chambers would seem to be expensive in comparison to the overall value of the firearm. How much is a new revolver worth?

[rodwha]

His revolver is ~45 years old.

[dondiego]

His revolver is ~45 years old.

Got it.

[rodwha]

Can anyone supply chamber sizes for their .36 cal to compare? My understanding is they are north of 0.369".

[Chill Wills]

I'm with you on wanting to know what is usual and customary.

I need to look for what size reamers I have. I am far from setting this cylinder up to ream the chambers, but I still think the cylinder chamber mouths might be too small for the barrel. If this were a center fire cartridge revolver, I think this would be a very poor but fixable situation.