1858 Bore Specs ?

[hylander]

I can not find an answer anywhere, my Google-fu must be week.
I want to know the Land and groove specs for current model Uberti and Pietta 1858 in .44
Also chamber specs would be nice also
So has anyone here actually slugged theirs to find out ?

[Baron von Trollwhack]

Uberti bore specs are noted on the Cimarron Site.

BvT

[Omnivore]

Dixie Gun Works lists a lot of the specs in their product descriptions. The Uberti 44 is supposed to have .450" Chambers and a .450" groove diameter. IIRC, the bore is supposed to be .440". I slugged my Pietta once, but I forget the actuall reading, and it's not easy to get right due to the uneven number of grooves.

Note that the chamber and groove dia. is the same in an Uberti. Pietta uses a chamber smaller than the groove diameter by several thousandths. Why they do this has never been explained, and what's more is the relationship (between chamber and groove) can be different for different models in the same caliber. Uberti's Colt Pocket police for example is the only one I've seen, IIRC, where they list the chamber being (as it is generally considered to be ideal) larger than the barrel groove diameter. Some people ream their chambers to three thou over groove dia. Note that a 29/64" reamer is .453"-.454" which would be about "right" assuming your barrel is of good enough quality, and has the right forcing cone, to make such things matter a whit.

All that being said; I haven't ever found where anyone has said that a particular set of specs will for sure make your repro Remington shoot better than some other. Some of the Piettas shoot very well in spite of having been built "wrong".

So don't sweat over it too much. For one thing, there are a lot of other factors that go into making a good revolver "good", and for another thing the Itallian repros, even the best ones in the 300-400 dollar range, are not built to modern standards of high quality even for a mass produced revolver, else they'd cost several times what they cost. The Pietta "Shooter's" model Remington for example is closer to a thousand bucks.

[hylander]

Thanks for the input.
So if I'm reading the Cimarron specs correct, the groove is .458 :shock:
That seems why oversized, seeing how when a ball is pushed into the cylinder it is down sized to
about .450
So that leaves .008 of free play between ball and groove when fired. So the ball is riding on the lands
and making no contact with the grooves leaving space for gases to leak by.
Does not seem like a good thing, and seems accuracy would suffer

[Win94ae]

I just slugged my Pietta 1858 bore with a .451 ball.

http://img.photobucket.com/albums/v39/justgoto/Guns%203/44roundballrifling_zps79aa1cc2.jpg

The area at the center has been touched ever so lightly by the grove; all the other grove locations have been scored fairly well.
The smallest reading my mic finds is .447, that is dealing with the 7 groves.

[Baron von Trollwhack]

Hmmm? What usually happens to an undersized ball in an oversized bore?

BvT

[hylander]

Hmmm? What usually happens to an undersized ball in an oversized bore?

BvT

I know what your thinking, the balls blown out to fill the gaps.
But this can also be a cause of leading because hot gases are being blown around the ball

[Omnivore]

if I'm reading the Cimarron specs correct, the groove is .458

I've never seen it listed as being that large. Any time I've seen the specs listed the Uberti it's been .450 chambers and .450 groove. Never even heard of a repro 44 with a .458 groove diameter. I just checked Cimmaron and they don't list any specs of that kind other than "caliber; 44", nor does Buffalo Arms, which sells the Cimmaron Ubertis here in Idaho. Dixie and others I've seen list it as .450/.450.

Doesn't matter though-- you won't know how it will shoot just by reading bore numbers on a web site, i.e. there's nothing to figure out there. The best way to know is to get the revolver you like, try it out with several loads/balls/bullets and see what happens. After using the Pietta and Uberti Remingtons, I'd be more worried about action, indexing, and how the loading ram does or does not impinge on the chamber mouth when seating full loads, but no one ever talks about the latter.

[hylander]

Well a friend brought over his Uberti 1858 today.
I Mic'ed the chambers and slugged bore.
He has only fired this revolver once a few years ago and did not check accuracy on paper.

Chambers: .450
Bore: .440
Grooves: .458

Also I called Bennelli which imports Uberti.
They gave me these exact numbers.
Only difference is his 1858 has 6 lands and grooves, the new ones are advertised with 7

[dikman]

I can't find the figures at the moment, but sometime ago I made a casting of one of my Uberti's chambers, and the chamber is actually tapered from the mouth back.

[Baron von Trollwhack]

No, in C&B revolvers the undersized ball from the undersized cylinder chambers do not blow out to fill the oversized bores. That relationship persists to provide LOUSY accuracy just as it does in cartridge guns. My comment was sarcasm at the fumbling about on the problem. As in a cartridge gun, the ball leaving in the cylinder must be slightly over cylinder and barrel groove groove to seal, and to support accuracy. The Italian guns are notorious for this , most likely as a liability issue, regarding pressure. The cure is to open cylinders in the guns to discharge a ball into the throat and seal the bore, with proper cylinder gap. All this assumes proper timing a cylinders on axis with the barrel. BvT

[hylander]

No, in C&B revolvers the undersized ball from the undersized cylinder chambers do not blow out to fill the oversized bores. That relationship persists to provide LOUSY accuracy just as it does in cartridge guns. My comment was sarcasm at the fumbling about on the problem. As in a cartridge gun, the ball leaving in the cylinder must be slightly over cylinder and barrel groove groove to seal, and to support accuracy. The Italian guns are notorious for this , most likely as a liability issue, regarding pressure. The cure is to open cylinders in the guns to discharge a ball into the throat and seal the bore, with proper cylinder gap. All this assumes proper timing a cylinders on axis with the barrel. BvT

I was hoping it was Sarcasm, I agree with you 100%
I just don't understand why they chose to make it so off, I thought maybe I was missing something.
I was leaning toward the Uberti because off all the input that Ubertis have better fit and finish than Pietta.
However I am leaning back to Pietta as the biggest grooves I have seen ot heard about are .451.
I do not want to try to open up the chambers to .460 as that is a lot of meat to be removing on the tin cylinders and then try to get a round ball mold made in .460