Wedge won't stay in

[Columbus]

I have an unfired Uberti Baby Dragoon made in 2015. Nice little gun but the wedge will not stay in place. The slot in the arbor may be a bit too long or the wedge a bit too narrow. If it's the arbor slot, is there a way to fix it? I have a new wedge coming from Taylor's but am not sure that's going to fix the issue. I've only dry fired the gun, don't want to have to go looking downrange for the barrel.

 

[Zonie]

When you install the wedge are you just pushing it in place with your finger or are you giving it a light tap with something like a screw driver handle to seat it?

Actually, the wedge should fit loosely into and through the slot in the cylinder arbor if the barrel is not in place.

With the barrel in place, the wedge should make contact with the front of the arbor slot furthermost from the frame forcing the barrel rearward as it is pushed further thru the slot.

In the process of doing this, the barrel will not only move closer to the frame, removing any gap between the lower area of the barrel and the front of the frame but, the end of the arbor should bottom out in the arbor hole in the barrel. Once this is done, any further attempt to drive the wedge further thru the barrel should make the interference between the arbor's end and the bottom of the arbor hole in the barrel greater, locking up the entire assembly.

 

[bang]

Have checked the arbor fit?
Remove barrel. Remove cylinder. Install barrel but turn to miss frame mating surface. Does the barrel frame over lap the the cylinder frame? If so the arbor hole is deeper than the arbor length and you need to correct it. Simple solution is to drop various thicknesses of washers in the arbor hole then repeat fit check till mating surfaces just positively touch. May have to thin down a washer to fine tune it. Once fit is established grease the arbor end. Drop a dot of epoxy on bottom of hole and drop in the washer. Install barrel and wedge and let set. Disassemble and clean. Any flakes of glue can be picked out but if you use just a small dot there won't be any. Then fully reassemble then deal with wedge.
I had to do this on my Uberti Dragoon and a Walker.

 

[Columbus]

Have checked the arbor fit?
Remove barrel. Remove cylinder. Install barrel but turn to miss frame mating surface. Does the barrel frame over lap the the cylinder frame? If so the arbor hole is deeper than the arbor length and you need to correct it. Simple solution is to drop various thicknesses of washers in the arbor hole then repeat fit check till mating surfaces just positively touch. May have to thin down a washer to fine tune it. Once fit is established grease the arbor end. Drop a dot of epoxy on bottom of hole and drop in the washer. Install barrel and wedge and let set. Disassemble and clean. Any flakes of glue can be picked out but if you use just a small dot there won't be any. Then fully reassemble then deal with wedge.
I had to do this on my Uberti Dragoon and a Walker.

I don't quite understand this. How does the arbor hole effect this? The bbl frame has to go against the cylinder frame and it seems to me that once they make contact the arbor hole depth would be irrelevant.

 

[Zonie]

Although the barrel frame stops on the front of the receiver frame, if the nose of the arbor is not bottomed out in the barrel frames arbor hole because it is too deep, the barrel will continue to be driven aft as the wedge is driven further in.

With the lower part of the barrel frame bottomed out on the receiver frame, the entire arbor will begin to bend, pointing the muzzle of the barrel upward and reducing the distance between the rear of the barrel and the face of the cylinder.
I've seen this happen to a point so severe that the barrel actually pinched the cylinder so the cylinder wouldn't turn.

 

[bang]

If the entire assembly is not as a solid mass the physical strength will be affected from all the forces.
The wedge pulling barrel back and shooting pressures pushing. Take all the slack out and the solidity of the mass negates the opposing forces.

 

[Columbus]

With the bbl turned to just miss the mating surface this is just a slight overlap. But with the bbl snugly fit against the frame there isn't much of the front of the arbor slot showing.

 

[bang]

The over lap is the concern. Afix a shim in the arbor hole to make the surfaces just touch. There are other way that require way more work but this method works and is the simplest.

 

[bang]

What's goes to happen is this will make the wedge path that much narrower and the wedge fit should get better because the barrel assembly will be bottomed out at the arbor true length not allowing the wedge to pull the barrel aft and force the assembly to become as one mass.

 

[Gun Tramp]

What's goes to happen is this will make the wedge path that much narrower and the wedge fit should get better

Then why won't a wider wedge work?

 

[Bad Karma]

Courtesy of @arcticap

 

[bang]

Then why won't a wider wedge work?

The assembly will pull the barrel and you will end up with tension pulling the barrel up. It will be noticable by the cylinder gap being smaller at the top and larger at the bottom. You want a solid fit of the arbor with the frame mating surfaces just touching. This will insure the barrel assembly is square to the cylinder. If you pull the barrel assembly with the wedge and cause the cylinder gap to not be symmetrical the alignment will be off. Same goes for left and right. If the gun shoots left or right the mating surface is not square. We can cover that once you get the first tuning item fixed. Cylinder gap preference is as minimal as possible but the cylinder does not bind and the gap it the same top to bottom. The only thing that sets that is a solid arbor fit to touching the mating surface. It's the wedge that stabilizes that.
Wood bow has the illustration that perfectly shows this.

 

[bang]

The left n right issue is rare. If the cylinder gap goes past a symmetrical .008 the trimming the mating surface of the barrel is what fixed that. It brings the barrel closer to the cylinder.
Do you know what the cylinder gap is now?
I can assure you even the minute extra depth of the arbor hole compared to the actual arbor length will cause poor wedge fit.
If you suspect wedge damage and see evidence of it on the wedge or mauling at the frame or arbor the cause is slack in the mass due to poor arbor fit.

 

[M. De Land]

I totally agree that the lug has to be tuned to the wedge arbor, slot fit but the notion that the arbor has to bottom out in the well to make a solid lock up for the gun to be accurate is pure BS. It is however convenient for consistent wedge depth but so is a depth block under the wedge ledge.
An easy fix for this is to grease the well and end of the arbor and put in a bit of glass bedding at the well bottom. Put the barrel back on and let it set up. I think it a better fix than screws in the end of the arbor or slugs/washers down the well bore. It will be a form fit and can be easily remove if necessary.
Actually, parallel slot fit , either side of the arbor slot, has more to do with windage than does the lower lug fit. The lower lug needs to be square across it's width and the alignment pins snug. It also needs to be under enough tension to stop the natural bend down of the barrel when the ball or bullet hits the forcing cone so the ball will go straight out and not shoot high or low. The snug lug pins and the wedge also stop the barrel torque from the ball inertia into the helix of the rifling. This is why the lug pins fit and the thickness of the wedge in the slots is important and not just the wedge width.

 

[bang]

Deland if it's BS then why suggest a fix?
If it's BS why it fixing it noted in every tuning the Colt recommendations?
Self contradiction creates irrelevance.

 

[Columbus]

With the bbl assembled the wedge is only making contact with the arbor on one side. I found the arbor slot opening on the left side (where there's no contact) measures .540 and on the right side (only contact point) it measures .534. Maybe I need a wedge that's slightly more of a wedge.

 

[huntinguy]

The wedge should touch only one side of the barrel and the opposite side of the cylinder pin slot.
I have seen and done my 1851 by putting a screw in the end of the cylinder pin and filed the screw head until I had proper fit. If done correctly, the barrel will have the proper gap when the bottom of the barrel is mated to the frame.
In short the frame to barrel fit works with the cylinder pin to barrel fit to align the barrel, set the gap and hold the two parts together.
Quite simple, quite intricate design.

 

[Columbus]

The wedge should touch only one side of the barrel and the opposite side of the cylinder pin slot.
I have seen and done my 1851 by putting a screw in the end of the cylinder pin and filed the screw head until I had proper fit. If done correctly, the barrel will have the proper gap when the bottom of the barrel is mated to the frame.
In short the frame to barrel fit works with the cylinder pin to barrel fit to align the barrel, set the gap and hold the two parts together.
Quite simple, quite intricate design.

Then that right there is a problem because my wedge makes no contact on the left side on the bbl or arbor at all.

 

[SPQR70AD]

what a horrible primitive system the Colt has. The 1858 Remington was 50 years ahead of the Colt

 

[Gun Tramp]

Lest we forget, wedge (key) fit was important enough on originals for it to be numbered to its revolver.

what a horrible primitive system the Colt has.

Ah, but the Remington must be cleaned from the muzzle!