Measuring C&B Revolver Chambers

Mad_Dog · January 25, 2013, 11:32:36 AM

Hello! I'd like to measure the chambers of my C&B revolver (Pietta Remington), but I don't have access to a pin guage set. Could one "slug" the chambers by removing the nipples, seating round-balls, and then punching them out through the nipple hole?

If I were to slug the chambers (and my bore while I'm at it), what would be the best type of tool to measure the slugs? Caliper? Micrometer? (what's the difference?)

thanks,
Mad Dog

Coffinmaker · January 25, 2013, 01:27:16 PM

Yes. You can slug the chambers by removing the cone to drive the ball back out. Use a cast ball and measure worth a micrometer.

Coffinmaker

Billy Bristol · January 25, 2013, 02:09:26 PM

micrometers are much more accurate than calipers. You can mike within a few tenths with micrometers but calipers can be off by 1/2 thousand or more depending on feel when closing them.

Pettifogger · January 25, 2013, 06:46:27 PM

For what we are doing I just use a high quality caliper and measure the chambers directly. The ball has to be larger than the chamber so chamber tolerances at the micrometer level simply aren't needed.

Mad_Dog · January 26, 2013, 08:29:37 PM

Quote from: Pettifogger on January 25, 2013, 06:46:27 PM
For what we are doing I just use a high quality caliper and measure the chambers directly. The ball has to be larger than the chamber so chamber tolerances at the micrometer level simply aren't needed.

Will that suffice for seeing if the chambers are bigger than the bore? If so then I'll just borrow a buddy's caliper

. If not, then I think a fellow at work has a micrometer I can use if I bring in the slugs.

-GB

St. George · January 26, 2013, 10:00:43 PM

Out of curiosity, are you experiencing lead shaving and undue fouling?

Scouts Out!

Mad_Dog · January 27, 2013, 01:49:15 PM

Quote from: St. George on January 26, 2013, 10:00:43 PM
Out of curiosity, are you experiencing lead shaving and undue fouling?
Scouts Out!

I am indeed shaving lead with the DD-ROA conicals but I haven't tried any of my 451 round-balls yet. I only shot 5 cylinders full but didn't notice any undue fouling. It's another three weeks until I get to shoot it again, though, so I thought I would pass the time by measuring it instead

-Mad Dog

rifle · January 28, 2013, 10:21:14 AM

The chamers seem to be a fairly consistant few .001's in. smaller than the barrel groove diameter. That may let the bullet cant a hair going in the forcing cone.
Most likely there is a sharp edge at the beginning of the forcing cone at the breech end of the barrel that shaves a little lead. Takng that sharp edge off some may help the lead shaving to stop. Making sure the bullets go in "straight" may remedy the problem also.
The forcing cone may need touched up some with an 11 degree forcing cone reamer. Maybe widdened a little.
The alignment of the chambers to the bore may be off too.
There are plenty of qualified gunsmiths (or even Kitchen Table Gunsmiths) here to get one to take a look at the gun.
Using round balls can be more forgiving than conicals...if you can stand using the balls over the bullets. Some people don't care fer the lead ball and need the bullets.

Mad_Dog · January 29, 2013, 08:30:01 AM

Quote from: rifle on January 28, 2013, 10:21:14 AM
The chamers seem to be a fairly consistant few .001's in. smaller than the barrel groove diameter. That may let the bullet cant a hair going in the forcing cone.
Most likely there is a sharp edge at the beginning of the forcing cone at the breech end of the barrel that shaves a little lead. Takng that sharp edge off some may help the lead shaving to stop. Making sure the bullets go in "straight" may remedy the problem also.
The forcing cone may need touched up some with an 11 degree forcing cone reamer. Maybe widdened a little.
The alignment of the chambers to the bore may be off too.
There are plenty of qualified gunsmiths (or even Kitchen Table Gunsmiths) here to get one to take a look at the gun.
Using round balls can be more forgiving than conicals...if you can stand using the balls over the bullets. Some people don't care fer the lead ball and need the bullets.

Perhaps I misunderstood "shaving lead"... i meant that a little ring of lead is shaved off as I seat the conical (which proved rather difficult at times, so I'm not sure I'll be using the rest of these conicals). I also had to put them in upside down since they wouldn't fit under the rammer otherwhise. I did end up with goobers of the lube where the cylinder faces the breech of the barrel, but didn't notice any lead there.

That tendancy for the chambers to be slightly undersided relative to the bore is precisely why I want to measure them. I've read (too much time reading, not enough time shooting) that a revolver will be more accurate if the chambers are as big as the bore grooves or perhaps just a hair larger. Granted I'm sure the revolver is far more accurate than I am, but that doesn't mean I don't want it to be as accurate as possible

-Mad Dog

Delmonico · January 29, 2013, 09:05:28 AM

Take a case champhering tool and lightly break the edge on the front of the cylinder, it should fix the problem like it does with a brass case.

Pettifogger · January 29, 2013, 10:59:03 AM

Quote from: Mad_Dog on January 29, 2013, 08:30:01 AM
Perhaps I misunderstood "shaving lead"... i meant that a little ring of lead is shaved off as I seat the conical (which proved rather difficult at times, so I'm not sure I'll be using the rest of these conicals). I also had to put them in upside down since they wouldn't fit under the rammer otherwhise. I did end up with goobers of the lube where the cylinder faces the breech of the barrel, but didn't notice any lead there.

That tendancy for the chambers to be slightly undersided relative to the bore is precisely why I want to measure them. I've read (too much time reading, not enough time shooting) that a revolver will be more accurate if the chambers are as big as the bore grooves or perhaps just a hair larger. Granted I'm sure the revolver is far more accurate than I am, but that doesn't mean I don't want it to be as accurate as possible

-Mad Dog

If you start measuring the chambers on C&B revolvers I think you will be surprised to find that almost every cylinder/chamber on every brand is BELOW bore size. A lot of the .44s have a bore size around .452. Yet the chambers are often .445 - .446. Aside from easing seating in the chambers, one of the reasons C&B bullets should be PURE lead is that they bump up when they hit the forcing cone. If you were in a muzzle loading sport and had to be able to shoot one inch groups at fifty meters, then this measurement might make some difference. A CAS ranges most people (who have never measured the chamber throats, ignorance is bliss

) find their guns produce excellent accuracy. I also would not put an 11 degree forcing cone on a C&B.

Fox Creek Kid · February 05, 2013, 04:25:07 AM

Quote from: Pettifogger on January 29, 2013, 10:59:03 AM...I also would not put an 11 degree forcing cone on a C&B.

Why not?

Pettifogger · February 05, 2013, 07:22:34 PM

I wish Mako were still on the wire. He could make a beautiful drawing. I don't have any drawing software on my Mac. If I can get some time maybe I can make a sketch, photograph it and then post it.

GunClick Rick · February 14, 2013, 10:47:28 PM

Should you mic the cylinder from the nipples so the nipples are all the same ..to the flat end of the cylinder?