Uberti 1860 short arbor fix

French Colonial said:

I almost hate to post this because of the negative reaction some will have, but here goes.

I bought a Uberti 1851 navy only because that is what my Great Grandfather carried in the civil war, not really my time period of interest.

Contrary to what others believe it shot great right out of the box with round balls, not so much with conicals or paper cartridges.

I see no reason to mess with it and I will not be playing with the arbor, YMMV.

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FC, agree, my 51 has zero short arbor symptoms, is dead nuts accurate. Maybe it is an Uberti crap shoot but mine has been fine out the box. Purchased 4/23.

CaptainVane said:

FC, agree, my 51 has zero short arbor symptoms, is dead nuts accurate. Maybe it is an Uberti manure shoot but mine has been fine out the box. Purchased 4/23.

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Yap, like I said, they're too weak to do the things the 44's can do . . . but they CAN eventually and they still aren't "as original" so . . . have fun

Mike

Sure, Mike. What exactly do you want a photo of? The pistol itself or a certain part?

Jaegermeister said:

Sure, Mike. What exactly do you want a photo of? The pistol itself or a certain part?

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How about down the arbor hole and the end of the arbor.

Mike

I’ll get ‘em tomorrow.

Here you go.

Jagermeister the reason yours is dead on is because it's been modified. The Philips screw head in the hole is a dead giveaway.

Yes, I just noticed that when taking and posting the photos. Sure feels great having a Goonerized gun! Solid reliability.

45D said:

Yup, so taking an unknown spacer thickness and checking the frame/ barrel lug gap ( because the spacer is too thick) will allow a "known" number ( measureed) to close that space down (with wedge in but not in final position of course) 1st step.
That's finding the fulcrum.
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After that, closing down the endshake to your spec will have the element of compression thrown in (wedge). Obviously, thumb pressure won't suffice because it's not enough to end up with a consistent spec. You'll need a good smack with a plastic head machinist hammer. Adjusting the spacer to get your spec will be tedious depending on your number but your wedge slot should stay the same. I, on the other hand, remove material from the end of the arbor (much more control) to get to my .0025" - .003" spec. But, my method opens the width of the wedge slot slightly so the need for a forward bearing for the wedge
becomes necessary ( or I could make a new wedge or buy new wedges). Since I'm not in the wedge making business, an "adjustable" bearing makes things much simpler and gives the end user options.

Mike

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I’m showing my ignorance of open top revolvers here.
I should have enough spacer/plug in the arbor hole so that I end up with about .003 barrel gap no matter what the barrel lug/frame fit is.

Shiloh said:

I’m showing my ignorance of open top revolvers here.
I should have enough spacer/plug in the arbor hole so that I end up with about .003 barrel gap no matter what the barrel lug/frame fit is.

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Well, your barrel lug / frame is a "given" so you start measuring for your .003" endshake ( bbl/cyl clearance) after the lug and frame make contact.
Before lug /frame contact -

And meeting WITH wedge started -

Now you can dress the spacer to get your endshake (always with wedge in with tension).

Mike

"I should have enough spacer/plug in the arbor hole so that I end up with about .003 barrel gap no matter what the barrel lug/frame fit is".

No.

45D provides the answer, not just a one word comment that is of zero help.

I was a mechanic/technician for 30 years and 45D had to explain to me the fundamentals of an Open Top. It was outside my experience and I had no basis of reference.

Gravitate to people that supply answers.

45D:

Next step in my understanding of this is once you contact the frame with the barrel assembly, does wedge force then bend the front assembly up making for an uneven gap top and bottom, of the cylinder?

If the arbor is short, then yes, the barrel is drawn in tighter which angles it upwards.

If you want to keep the barrel square to the cylinder and the endshake is too large (after adjusting arbor length) then a little will have to come off the arbor and the frame lug to draw it in closer.

Otherwise, shortening the arbor (or the shim) will draw the barrel in closer reducing the endshake. But the barrel won't be exactly in line with the cylinder - angling up some.

Smokerr said:

45D:

Next step in my understanding of this is once you contact the frame with the barrel assembly, does wedge force then bend the front assembly up making for an uneven gap top and bottom, of the cylinder?

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Thank you, makes perfect sense.

Smokerr said:

45D:

Next step in my understanding of this is once you contact the frame with the barrel assembly, does wedge force then bend the front assembly up making for an uneven gap top and bottom, of the cylinder?

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Normally, there is still plenty of "fitment" when the frame and lug meet ( barrel would be pointing down). By the time you get close to your "endshake" number, you'll be able to see any "forcing cone" / "cyl face" alignment problem. You can "sight check" a lot of it ( top to bottom but don't forget to look at "east and west" (3 &9 o'clock). The trick here is to get the wedge in tight with no "interference" (binding) with a feeler gauge of .0015" - .002" . At that point, dress (file) then sand/polish the forcing cone to your spec.
The barrel will be straight, "endshake" will be yours and the wedge will be tight!

Remember in all the other threads about how accurate these revolvers are "just like they are" ? The barrel alignment will always be close unless you go nuts dressing the arbor to do a "stupid" test !!! Most of the barrels have a decent amount of runout ( just look at the ends of the barrel!!). That being the case, once done, you'll be able to sight it in and it will be the same from then on (unless you choose to change it). The differences in cylinder chamber alignment with bore alignment of barrel and the bung in the frame the barrel screws into with top strap guns is generally no better (production guns).

The open-top is capable of extreme accuracy.

Mike

Yea, I got lucky a few weeks back and got a 1 inch group of 6 shots with the 47 Walker and an unmentionable cylinder. I was stunned (25 Yards).

No gun I ever shot had that kind of capability. I am happy with 2-3 inches these days. I am not getting competitive about it, its just fun (don't ask me about my target rifles!)

I'll do a step by step on the 3 that I'm working on and post pics this afternoon.
(2 Uberti's 1 Pietta)

Mike

45D: That would be much appreciated. I always gravitated to visual first then build a mental model as it were.

Call me a Fan Boy if you want, but I think its beyond awesome to have someone like 45D who shares his work like this. Clearly its an unprecedented understanding of the platform. Clearly has gone from the realm of opinions to facts.

Bad Karma gets a major hat tip with pulling up and posting the Colt information. Details I had not seen ref to and how beautifully it fits in with 45D work.

There will continue to be opinions and naysayers but when you have facts on your side, it reduces the opinions to irrelevance and they can be called on it.

Smokerr said:

Call me a Fan Boy if you want, but I think its beyond awesome to have someone like 45D who shares his work like this.

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Join the club! Mike is a first class human being.