Chamber Inside Diameter

[RLBishop]

I purchased a Uberti 2nd Model Dragoon .44 cal. The thing is beautiful. I did some reading on this site regarding conical bullets and paper cartridges. I have successfully loaded and fired paper cartridges using .454" round balls. The reading that I did to attempt to reproduce a Civil War conical in a paper cartridge said the conical weighed 219 grains. I purchased a mold from Lee that produces a 220 grain .456" flat base conical. Here's the wierd part. My father-in-law also has a Uberti Whitneyville Dragoon in .44. The conicals that we poured will drop into his Dragoon's chambers, down to the second grease ring. I can't get them to even start. They just sit there and will not go in. I used a set of dial caliper gauges and his chambers measured .458" at the mouth. Mine are measuring .440" at the mouth. What gives? Were mine bored wrong? :idunno:

 

[curator]

Welcome to the wonderful world of cap & ball revolver replicas. What you describe is pretty common. While many people get lucky and buy a C&B revolver that has chambers bored near to the actual groove diameter of the barrel, some are not as lucky. I have had several revolvers that were a bad match as well. My Uberti 3rd model Dragoon came with .450 diameter chambers and a .456 barrel-groove diameter. I have a ASM Walker that is the poster child for miss-matched diameters. It came with .439-440 diameter chambers and a .468 groove diameter barrel. This is not exclusive to any manufacturer. The obvious cure is to get the chambers reamed to groove diameter +.001 or even .002", then load a ball/bullet at least .002" over this diameter.

 

[Zonie]

I don't know if your chambers were bored wrong but the .440 diameter you say your reading is undersized according to the 2009 Dixie Gunworks catalog.

It says your bore should be .440, grooves .456 and your chambers .449.

Somewhere there is probably a .449 diameter reamer but the only ones I find are Brownells chambering reamers which may not work.

A adjustable reamer in the 7/16-15-32 size would work if you have a way to drive it and to adjust it to the right diameter.
Link: http://drillsandcutters.com/reamers_adjustable.aspx

Another possibility is a good gunsmith in your area may have a reamer of just the right size or he could hone the chambers to .449.

Of course you can always try to get ahold of Uberti and ask them if the gun was made wrong.
They might send you a cylinder with the correct size chambers.

 

[RLBishop]

Thanks for the input, guys. I did send an e-mail to Dixie Gunworks asking them if it was something that they could address or if they had a number for me to contact Uberti. I'm not a machinist and am unsure of the abilities of my local gunsmiths. I think I recall hearing the local shops send items out for any kind of machine work outside of drilling and tapping or blueing. :v

 

[aeatwood]

If you use a pure lead ball, the BP will usually flatten it out and bump it up to fill the grooves. If it does, it will probably shoot pretty well at short range, but a projectile that is shorter than it is wide will usually begin to wander pretty good at 50 yards are beyond.

Lee makes those conicals in 2 sizes, .450" and .456". It might be the smaller one would work for you. The base band on it is smaller than the driving bands so it will help center the bullet in the chamber, and keep it from getting canted off-center by the rammer.

How did you measure the chamber mouth diameter? Did you drive a slug in and out and measure it? Just using a micrometer will usually get you a slightly smaller reading than the actual number. Ideally, you wand to measure with plug gauges.

Alan

 

[CoyoteJoe]

For best accuracy from a revolver it is important that the ball or bullet be at least groove diameter and many, perhaps most, C&B revolvers have undersized chambers. Lots of people use a 29/64" reamer which cuts .453". You won't find one at True Value but they can be ordered from several online dealers for ten bucks or so. If you don't feel confident to do it yourself just take the cylinder and reamer to a gunsmith or machine shop.

 

[robertdale]

check out MSM supply. .they are vendors of tools and supplies for machine shops. you need a straight chucking reamer to size of bore grooves plus .002 +-. use a drill press to drill and tap a 1/4 x 20 hole in a steel plate approx. 4-6inches square x 1/4 thick, approx. bolt the cyl to the plate thru pin hole then slowly ream ,lots of oil, to a depth that is 3/8" above end of chamber. use care to get reamer centered well, turn by hand reverse to use shoulder on reamer to center.use a reamer that will fit a ball tight. this is tricky part. not a lot of ball sizes avail now.the chambers can be a bit larger to get the right size. just use 15-20 grn. loads with filler to get to face of chamber. lube and test fire. this always made my revolvers shoot very well.
good luck. :v

 

[qualibra]

Hello .

Norway here !

I had a Dragoon with the same problem .
I bought Brownells throatreamer, and it worked
like a charm without the pilot on .
It cut those fue thous effortless and allmost by its own weight without the need for handpressure and together with a T- bar handle .(thats how sharp it is)

Just place the sylinder chambers pointing towards ceiling and let it cut .
The gun did improve on paper .
The chambers was .448 and the reamer opened them up to .4525 .
That happened to be equal to groove dm .
Good luck !

 

[wulf]

I know it is a different cal. size...but I reamed
all my 36's [375] out to 380...with the super
shallow rifling it sure made a big difference.
Wulf