Trying to understand this “short arbor” on Uberti revolvers

[Gun Tramp]

Anyone wants to,give Uberti USA their thoughts on the matter can send an email through their contact on the website.

I checked into that (#45 above). That's for Stoeger marked guns only, just as stated in the contact info. The chap I tried corresponding with explained that clearly and immediately.

 

[Bad Karma]

We’ll see what sort of response I get from them. I still don’t think it hurts to flood the CSR’s... perhaps they’ll notice it in Italy? I should note that Italian motorcycle manufacturer Moto Guzzi has been resistant to market responses since 1921 so there’s that...

 

[Old Hawkeye]

I have been following this thread intently, as I have a Uberti 1851 London model. I checked mine for the "short arbor thing". What I found was mine was not "short" at all, but rather fit "exactly" to the length it should be. The wedge is tight & I have to tap it with a plastic punch to get it out & have to tap it slightly with a small hammer to seat it. I have shot close to 500 rounds through it, yet the cylinder has no bolt marks on it's circumference or in the bolt stop recesses & looks as new as the day I bought it. Maybe I just got lucky, but it is the best timed & functioning revolver of any kind I have ever owned. It's fit & finish is much better than any of the Colt built 2nd or 3rd Generation Navy's I have seen & shot. Not sure when it was made but, IIRC, I bought it new less than ten years ago. Could Uberti QC vary that much from gun to gun or year to year? I haven't much experience with C&B revolvers, so thought I'd add my two cents and see what you fellas think or why my Navy is so perfectly "fit & timed".

 

[denster]

I have been following this thread intently, as I have a Uberti 1851 London model. I checked mine for the "short arbor thing". What I found was mine was not "short" at all, but rather fit "exactly" to the length it should be. The wedge is tight & I have to tap it with a plastic punch to get it out & have to tap it slightly with a small hammer to seat it. I have shot close to 500 rounds through it, yet the cylinder has no bolt marks on it's circumference or in the bolt stop recesses & looks as new as the day I bought it. Maybe I just got lucky, but it is the best timed & functioning revolver of any kind I have ever owned. It's fit & finish is much better than any of the Colt built 2nd or 3rd Generation Navy's I have seen & shot. Not sure when it was made but, IIRC, I bought it new less than ten years ago. Could Uberti QC vary that much from gun to gun or year to year? I haven't much experience with C&B revolvers, so thought I'd add my two cents and see what you fellas think or why my Navy is so perfectly "fit & timed".

It is most likely that your arbor is short. The most probable reason that it appears not to be is likely you are careful enough with your revovler that you have not forced the arbor hole in the barrel over the increased diameter of the arbor that Uberti used to try to correct the problem. As long as you are careful assembling your revolver you will likely get by with it for some time.

 

[M. De Land]

I have been following this thread intently, as I have a Uberti 1851 London model. I checked mine for the "short arbor thing". What I found was mine was not "short" at all, but rather fit "exactly" to the length it should be. The wedge is tight & I have to tap it with a plastic punch to get it out & have to tap it slightly with a small hammer to seat it. I have shot close to 500 rounds through it, yet the cylinder has no bolt marks on it's circumference or in the bolt stop recesses & looks as new as the day I bought it. Maybe I just got lucky, but it is the best timed & functioning revolver of any kind I have ever owned. It's fit & finish is much better than any of the Colt built 2nd or 3rd Generation Navy's I have seen & shot. Not sure when it was made but, IIRC, I bought it new less than ten years ago. Could Uberti QC vary that much from gun to gun or year to year? I haven't much experience with C&B revolvers, so thought I'd add my two cents and see what you fellas think or why my Navy is so perfectly "fit & timed".

You may want to check and make sure your bolt is actually dropping to the bottom of the cylinder notches as it doens't sound like they are.. If the bolt drop is shallow there is a good chance it will start skipping out of lock up as it gets some more wear and the notch edges get battered up. I'd check the notch edges for any signs of battering or deformation from a shallow bolt drop.

 

[Old Hawkeye]

You may want to check and make sure your bolt is actually dropping to the bottom of the cylinder notches as it doens't sound like they are.. If the bolt drop is shallow there is a good chance it will start skipping out of lock up as it gets some more wear and the notch edges get battered up. I'd check the notch edges for any signs of battering or deformation from a shallow bolt drop.

Bolt drop appears to be fine. No signs of any "battering or deformation" anywhere on the recesses, at least for now. I'll keep an eye on it. Thanks for the heads up!

 

[Old Hawkeye]

It is most likely that your arbor is short. The most probable reason that it appears not to be is likely you are careful enough with your revovler that you have not forced the arbor hole in the barrel over the increased diameter of the arbor that Uberti used to try to correct the problem. As long as you are careful assembling your revolver you will likely get by with it for some time.

I put the revolver together like the picture in post #50 & the front face of the bottom of the frame meets up exactly with the bottom flat of the barrel assembly. As far as I can tell the arbor is bottoming out, as all the wear marks are on the front face of the arbor tube & not on the side. I'll try to measure things with my calipers & see what I can determine. The way my revolver is, the face of the arbor is flat but the bottom of the hole "appears" rounded. So, I am assuming the arbor should make contact at the end of the straight wall portion of the hole where the hole meets the rounded bottom. Is that correct?

 

[denster]

I put the revolver together like the picture in post #50 & the front face of the bottom of the frame meets up exactly with the bottom flat of the barrel assembly. As far as I can tell the arbor is bottoming out, as all the wear marks are on the front face of the arbor tube & not on the side. I'll try to measure things with my calipers & see what I can determine. The way my revolver is, the face of the arbor is flat but the bottom of the hole "appears" rounded. So, I am assuming the arbor should make contact at the end of the straight wall portion of the hole where the hole meets the rounded bottom. Is that correct?

That your revolver matches post #50 only indicates you have not wallowed out the arbor hole to any degree. You are correct depth is measured by the straight wall side.

 

[Old Hawkeye]

That your revolver matches post #50 only indicates you have not wallowed out the arbor hole to any degree. You are correct depth is measured by the straight wall side.

My revolver does NOT match the pic in post #50. The barrel assembly does NOT go past the front of the frame. I measured the hole & the position the barrel assembly is on the arbor when assembled & there is no slop. My arbor is NOT short! The arbor CANNOT be forced any further in the hole, no matter how "wallowed out" the arbor hole is, as it is bottoming out. It fits no differently than the Colt's I've had. In fact, it fits better. Guess I'll just be thankful & hang on to this one. Sold my Colt because I felt this Uberti was a better gun. Seems I was right for a change. Thanks for the insight & input. BTW, date code is CN.

 

[denster]

My revolver does NOT match the pic in post #50. The barrel assembly does NOT go past the front of the frame. I measured the hole & the position the barrel assembly is on the arbor when assembled & there is no slop. My arbor is NOT short! The arbor CANNOT be forced any further in the hole, no matter how "wallowed out" the arbor hole is, as it is bottoming out. It fits no differently than the Colt's I've had. In fact, it fits better. Guess I'll just be thankful & hang on to this one. Sold my Colt because I felt this Uberti was a better gun. Seems I was right for a change. Thanks for the insight & input. BTW, date code is CN.

What I meant was if you assembled your revolver as in post #50 and the barrel did not extend past the frame the hole is not damaged. Your gun was made in 2015 well within the CNC period. If you want to check for certain get a washer that fits the arbor hole. Measure it's thickness and drop it into the arbor hole then reassemble. Measure the gap between frame and barrel lug with your calipers. If your arbor is the correct length then the gap should be the same as washer thickness.

 

[M. De Land]

My revolver does NOT match the pic in post #50. The barrel assembly does NOT go past the front of the frame. I measured the hole & the position the barrel assembly is on the arbor when assembled & there is no slop. My arbor is NOT short! The arbor CANNOT be forced any further in the hole, no matter how "wallowed out" the arbor hole is, as it is bottoming out. It fits no differently than the Colt's I've had. In fact, it fits better. Guess I'll just be thankful & hang on to this one. Sold my Colt because I felt this Uberti was a better gun. Seems I was right for a change. Thanks for the insight & input. BTW, date code is CN.

If the bolt is dropping as deep and as soon as it should be there will be a wear rub line at the lead in cut and bottom of the notch. This helps ease the bolt into the notch , slows cylinder rotation inertia for the impact of the bolt side into the stop wall of the notch. If the Bolt drop is shallow or late it will eventually batter the stop wall of the notch. Out of time is not really early bolt drop but rather late bolt lift.

 

[Old Hawkeye]

What I meant was if you assembled your revolver as in post #50 and the barrel did not extend past the frame the hole is not damaged. Your gun was made in 2015 well within the CNC period. If you want to check for certain get a washer that fits the arbor hole. Measure it's thickness and drop it into the arbor hole then reassemble. Measure the gap between frame and barrel lug with your calipers. If your arbor is the correct length then the gap should be the same as washer thickness.

I'll find a washer & try that. Thanks!

 

[Old Hawkeye]

If the bolt is dropping as deep and as soon as it should be there will be a wear rub line at the lead in cut and bottom of the notch. This helps ease the bolt into the notch , slows cylinder rotation inertia for the impact of the bolt side into the stop wall of the notch. If the Bolt drop is shallow or late it will eventually batter the stop wall of the notch. Out of time is not really early bolt drop but rather late bolt lift.

I know what you mean about the marks the bolt can make on the lead in cut & the batter marks that can happen to the stop wall, but I just can't tell on this gun because there are no tell tale marks that I can decipher. No rub marks, no dings, no batter marks, just a tiny bit of bluing wear on the notch edge on both sides of the notch & I mean "tiny". I'm just going to keep shooting it while looking for the things you mention. Hard part on these guns is you can't see the bolt with the cylinder in like you can on a S&W to "see" how it is acting.

 

[Gun Tramp]

"Four clicks to cock." First is half-cock notch, second is bolt dropping (rising) into bolt notch lead, third is bolt dropping into bolt notch, fourth is full-cock; third and fourth are often at the same time which is ok. If you only hear two clicks, the bolt is likely dropping directly (and incorrectly) into its notch rather than the notch lead. If this is the case, beware of peening of bolt notches on their lead side. Common with the Uberti's I've had. My apologies for this being far from the OP's question...

 

[M. De Land]

People tend to get all worked up about a rub line on the cylinder but unless the bolt is galling the cylinder it hurts nothing and actually has a benefit in that it acts like a tension brake on cylinder inertia to ease the bolt into lock up as it slams into the stop wall of the cylinder notch.
A bolt out of time will be late in clearing the notch as the hand tries to turn the cylinder before the bolt is clear.
In tuning a revolver the bolt edges and dome are smoothed up so they operate without cutting/galling any part of the cylinder. The bolt is harder steel than is the cylinder so we want it smooth where ever it makes contact.
If you ever get a chance to look over a revolve that has been "fanned" a lot you will get a very good object lesson in how bolt notches in a cylinder can get abused.
This is why bolt fit both through the frame window and into the cylinder notch , adequate drop timing and depth are all important. Early bolt drop is of almost no negative importance other than making a rub mark on the cylinder .

 

[M. De Land]

I presume that you understand that every time you cock an open top you are wiping the face of the upcoming chamber since as the cylinder rotates it is pushed into contact with the barrel.

Fouling in any black powder arm not only accumulates but gets baked on from repeated firing to where it must be removed for best accuracy and function. Lube , humidity, wadding , powder type, granulation and revolver fit all have a share in the fouling management.
The chamber mouths being the farthest out from the cylinder axis have the most leverage to stop cylinder movement there fore fouling accumulation on this radial axis has far more stoppage leverage than it does on the arbor which is closer to center of cylinder movement.

 

[denster]

Fouling in any black powder arm not only accumulates but gets baked on from repeated firing to where it must be removed for best accuracy and function. Lube , humidity, wadding , powder type, granulation and revolver fit all have a share in the fouling management.
The chamber mouths being the farthest out from the cylinder axis have the most leverage to stop cylinder movement there fore fouling accumulation on this radial axis has far more stoppage leverage than it does on the arbor which is closer to center of cylinder movement.

53 years of shooting repro Colt open tops and not once have I ever had one bind up from fouling on the cylinder face. I must be very lucky or you must be very unlucky.

 

[Phil Coffins]

Try shooting a Colt style revolver with out lubing the arbor before putting the cylinder on.

 

[M. De Land]

Lets take a 58 Rem or Ruger Old Army that has only a base pin through the cylinder and it will eventually foul enough to sluggishness or stoppage especially when shot in a match on a hot summer day. There is no arbor to stop rotation only a small diameter pin , the fouling stoppage is on the chamber faces or barrel face not the base pin .
The arbor in an open top is maybe twice the diameter and has ribs to hold lube to prevent cease up. Believe it or not the stoppage "you" say is occurring from the arbor is in reality coming from the chamber mouths or barrel face. Now it may be that your close gap is the reason for your success as I have not set one up that close to test .
Part of the purpose of the grease lube on the arbor is to seal the fouling out not only to lube the rotation, why would I shoot one without lube on the arbor.
Simply a different opinion from yours!

 

[Pete G]

Try shooting a Colt style revolver with out lubing the arbor before putting the cylinder on.

Why would anyone do that