Correcting Uberti Short Arbors?

[M. De Land]

All of this work and you can't spend five minutes correcting the arbor length. I guess I just don't understand the feeler gauge fetish and the desire for a flexible firer????

You have to get over the notion of making an open frame gun rigid like a solid frame gun because it never will be regardless if the arbor fills up the arbor well or not. The filled up (solid) arbor well does nothing for accuracy under the forward pressure load at firing as all the load is on the slots , wedge and lower lug not the end of the arbor. Open frame guns are designed with flex in mind. The trick is to get them to do the same thing every time and this happens with equal pressure load on both sides of the barrel in the slots, arbor slot and lower lug fit. The gun just doesn't care if there is some room at the end of the arbor and arbor well.
I'm reasonably sure that is why Uberti and early Pietta's did not go to the trouble to address this and yet Uberti went to a lot of trouble in the rest of the guns fit and finish early on and now Pietta is following suit.
Customers get ideas in there heads and demand change wither it makes any sense or not and so gun makers usually comply sooner or later.
I have no trouble fitting the arbor well but know from experience it just isn't that important to accuracy compared to other considerations.

 

[denster]

You have to get over the notion of making an open frame gun rigid like a solid frame gun because it never will be regardless if the arbor fills up the arbor well or not. The filled up (solid) arbor well does nothing for accuracy under the forward pressure load at firing as all the load is on the slots , wedge and lower lug not the end of the arbor. Open frame guns are designed with flex in mind. The trick is to get them to do the same thing every time and this happens with equal pressure load on both sides of the barrel in the slots, arbor slot and lower lug fit. The gun just doesn't care if there is some room at the end of the arbor and arbor well.
I'm reasonably sure that is why Uberti and early Pietta's did not go to the trouble to address this and yet Uberti went to a lot of trouble in the rest of the guns fit and finish early on and now Pietta is following suit.
Customers get ideas in there heads and demand change wither it makes any sense or not and so gun makers usually comply sooner or later.
I have no trouble fitting the arbor well but know from experience it just isn't that important to accuracy compared to other considerations.

I don't think I will get over it. Nor will many who use these guns hard in competition. You are just as free though to think that I am wrong and continue with your flexible firers.

 

[M. De Land]

I don't think I will get over it. Nor will many who use these guns hard in competition. You are just as free though to think that I am wrong and continue with your flexible firers.

Ain't America great?
You are free to think as you like but it won't change the design character of open frame guns. If they are set up right I believe my 60 is fully the accuracy equal of my match 58 which is a better than my ROA. It's just that they don't have the sighting capability advantage that is present on solid frame guns that allows them to take advanage of the accuracy potential.

 

[springfield art]

Ain't America great?
You are free to think as you like but it won't change the design character of open frame guns. If they are set up right I believe my 60 is fully the accuracy equal of my match 58 which is a better than my ROA. It's just that they don't have the sighting capability advantage that is present on solid frame guns that allows them to take advanage of the accuracy potential.

My recently found new-in-box Pietta Colt 1960 was mfg. 2017. I've heard they use CNC machinery nowadays, and I can believe it as it's really smooth and precise-fit! Beautiful finish, etc.

 

[M. De Land]

I don't think I will get over it. Nor will many who use these guns hard in competition. You are just as free though to think that I am wrong and continue with your flexible firers.

All open frame guns flex more than solid frame guns wither or not the arbor well is filled.

 

[Dashing Leper]

I have an Uberti 1860 Army made in 2019 that is the worst when it comes to short arbors: the gun would not wedge up at all until I glued in a shim. Over time the shim has 'broken in' and the gun still gets loose.

Well, today I just got another Uberti 1860, this time a 3-screw civilian model with its own set of problems. The boat from Italy must have sprung a leak because this is the second Uberti that I have gotten this month that had noticeable rust in it. This new 1860 civilian (proof year 2021) has a longer arbor than the previous gun. How do I know? Because the rusted nipples were so bad that I pulled off a Tuco shop fix by swapping cylinders and barrel assemblies, mating the 2019's front pieces to the 2021's frame. Whereas the wedge on the 2019 frame slipped all the way in with zero resistance, that same barrel/cylinder locks tight into the 2021 frame before the spring tab can barely make its way through the right side of the slot.

Hopefully this is an indication that Uberti has finally wised up and corrected the arbor length on their newest examples.

 

[1861 Springfield]

In my opinion it is a solution in search of a problem which is why Uberti did or does not correct it. Why would they go to the trouble of fitting the rest of the guns so well and leave the well long if it is a real issue?
First off in the button fix the guy purposely weakens the end of the arbor by drilling into the wedge slot for the button stem. Same deal when it is threaded for an adjustable screw. Second he filed the wedge to fit the slot better after inserting the button which should be hard and would make it difficult if not impossible to file.
The slots in the barrel and end of the arbor need to be fit to a properly shaped and hardened wedge not the other way around!

i agree its not an issue for folks who dont have to fool with everything they own.

 

[45D]

i agree its not an issue for folks who dont have to fool with everything they own.

But, for folks that want whats "close" to be "correct", there are things you can do . . .

Mike

 

[FA&FO]

I have gone over this many times in previous posts but it’s worth explaining here again for all to see.

Uberti builds guns to a price point. One of their shortcomings is that the arbor does not bottom out in the barrel lug as Colt originally designed. This means that the wedge is holding the barrel away from the cylinder, which shouldn’t be the case. As these interference fit parts wear, if tolerances stack up incorrectly in the revolver or if the gun is repeatedly over wedged then the barrel cams upward/inward from the contact area at the lower frame. This gun exhibits those issues. This is a fairly common fix in my shop and as such is reasonably priced. I call it “arbor correction”. It not only fixes these issues but it also strengthens the gun and makes it more accurate as the sight alignment doesn’t change every time your disassemble/reassemble the revolver.

 

[Festus]

I agree. I shimmed a couple of Uberti’s arbors with washers and they now shoot point of aim after I reassemble them. I have some Piettas that have perfect arbor lengths, and in the future will probably buy more because of this.

 

[Stantheman86]

I use tin foil to make a metal plug , to "shim" my arbor holes

It's worked so far and I shoot alot.

55 grain charges through my Walkers, many 100s of them . Not a single problem. Both arbor holes filled with tin foil .