Uberti Bolts and Cams

[John E.B. Rawton]

I have read over several posts on many forums, copying and pasting into my files for reference. The knowledge that has been shared has been of great value and I thank you.
I just purchased two uberti in an 1851 and an 1860. I have been doing some clean up on the actions, removing burrs and addressing some areas that were rubbing to the point of gouging like the side of the hand.
The actions are smooth and feels good but here is what I’ve noticed. The cylinder on each gun is starting to get peened pretty good. The block is hitting within the lead in but the geometry is off, smacking the rear edge of the lead ramp.
At the bolt cam I’ve found that the bolt leg is riding up onto the cam at about 4:00. It does not appear that I can stop this from occurring.
I went ahead and ordered two new hammers (one hammer had a bad cast at the sight) and bolts plus the Colt SA shop manual. I want to be able to get some useful life out of the new guns without them tearing themselves up after a few hundred rounds.
If nothing else my understanding of the action is increasing bit by bit as I come up this curve.

 

[44 Dave]

You may want to reshape the bolt head. They are often not very well fit.
The bolt/trigger spring can be lightened to about 5 lb. to press it down flush, I have shims under some and Wolf springs (that can be bent) on others.

 

[denster]

I have read over several posts on many forums, copying and pasting into my files for reference. The knowledge that has been shared has been of great value and I thank you.
I just purchased two uberti in an 1851 and an 1860. I have been doing some clean up on the actions, removing burrs and addressing some areas that were rubbing to the point of gouging like the side of the hand.
The actions are smooth and feels good but here is what I’ve noticed. The cylinder on each gun is starting to get peened pretty good. The block is hitting within the lead in but the geometry is off, smacking the rear edge of the lead ramp.
At the bolt cam I’ve found that the bolt leg is riding up onto the cam at about 4:00. It does not appear that I can stop this from occurring.
I went ahead and ordered two new hammers (one hammer had a bad cast at the sight) and bolts plus the Colt SA shop manual. I want to be able to get some useful life out of the new guns without them tearing themselves up after a few hundred rounds.
If nothing else my understanding of the action is increasing bit by bit as I come up this curve.

Im not quite sure what you are referring to but if you mean the bolt head is striking at the beginning of the lead then that is where it is supposed to strike if you mean it is striking at the end of the lead where the locking notch begins and it is peaning the notch then it is dropping late and you would need to trim a bit off the end of the bolt leg that rides on the cam. As to the bolt leg riding up on the cam it is supposed to do that to lower the bolt head.

 

[Hawg]

Pictures please.

 

[John E.B. Rawton]

Here are 3 of the cam on the hammer. I think thr wear notch is visable in the right side about 4:00.

 

[John E.B. Rawton]

In these 2 you can see the cylinder is getting peened at the beginning of the lead in. Obviously the block could be shaped to hit center but I still think it is skipping up due to the wear on the cam.

 

[Rachen]

it is supposed to strike if you mean it is striking at the end of the lead where the locking notch begins and it is peaning the notch then it is dropping late and you would need to trim a bit off the end of the bolt leg that rides on the cam. As to the bolt leg riding up on the cam it is supposed to do that to lower the bolt head.

This. You would have to trim/sand the bolt legs if you want to adjust the timing of where the bolt lands and retracts. Don't make any modifications to the actual locking stud of the bolt (the part that engages the cylinder). I have fitted several indexing pawls and bolts to my Pietta-built 1858 on a few occasions over the years and I always a piece of sandpaper, and when I got to the right dimensions, I would even out any burs and round out the edges a bit with a diamond-rod knife serration sharpener.

I have always mentioned in other places that in order to master shooting black powder firearms and SA cartridge revolvers, you would have to be somewhat of a gunsmith-in-training. Not advanced stuff, but enough to re-time a revolver action and do a bit of minor work on areas like the forcing cone if it is compressing the bullets too much and making them undersized when they reach the bore. Re-timing the action is one of the more important parts of keeping an old SA wheelgun in the fight. The pawl and the bolt are among the parts that wear down more easily and when you shoot a lot, you will find yourself having to replace them from time to time.

When you order spare action components for SA wheelguns, the pawl and the bolt are always oversized when they come from the factory. That is so you can re-time them and fit them into the particular gun that you are using. NEVER use a Dremel or any other motorized sander unless you are really a pro at them. A piece of sandpaper, knife honer and honing rod is perfectly adequate for the job. After I had got the desired timing from the mechanism, I usually go ahead and buff out the edges slightly on items like the pawl and the bolt legs. From my experience, sharp edges on these metallic items make them more prone to cracking during use. Rounding 'em out a bit prolongs their service life greatly.

 

[denster]

That little tick at 4 o'clock is not wear but a small casting defect and where it is located does not effect anything and should be ignored.
You have two problems with the bolt and cylinder. The bolt is dropping late and starting to peen the inside edge of the notch. To correct this you remove a small amount from the rear of the leg that rides on the cam just enough so the bolt drops at the beginning of the lead in. The second problem is the hand is a bit too long and is trying to rotate the cylinder before the bolt has completely cleared and is raising metal on the outside edge of the cylinder notch. To correct just remove a couple of thousandths from the top surface of the hand.

 

[John E.B. Rawton]

It is hard to see the scratches in the area I referred to but as I watched the action from underneath, I could see the bolt leg ride up at that notch versus dropping off the cam.
I will need to recheck the length of the pawl. I am pretty sure that the cylinder rotation is not getting to lock up until I pass full cock which causes me to relieve thumb pressure to travel forward back into full cock. It makes me think the pawl is already too short.

 

[denster]

If you got to lockup before full cock you would not be able to then get to full cock. Those raised ticks of metal on the outboard edge of the notch are just going to get worse.
As you cock the hammer the bolt leg rides on top of the cam until in the rotation it runs out of cam and drops. As the hammer falls that tapering flat pushes the leg of the bolt outward until it can snap over the top of the cam for the next cycle. That tick has no effect the scratches on the surface are not wear but grinding marks from when the cam was tapered if they bother you polish them out.
I'm just trying to be helpful here and I've been working on single actions for nearly 50 years.

 

[John E.B. Rawton]

Thanks denster, I appreciate the help. When I get back to it I will closely watch what happens when and post again.

 

[45 Dragoon]

J.E.B.,
What I see in the photos is early bolt drop (peening before the approach) and a bolt head that needs material removed from the rear. The bolt contact should be centered in the approach, forward of center is livable, rear of center is not. More than likely, the mark on the far edge of the locking notch (tall side) was caused by the bolt riding high on the approach (main reason rear of center is bad, front of center still gives you a fully dropped bolt).

Probably all you need is a new hand. If lockup is happening after you reach full cock, the hand is too short. A correct length hand will have lockup and full cock occurring simultaneously. That being fixed, more than likely bolt drop should be close to correct.
I think a new hand may solve your problem.

The cam height could be reduced by about a 1/3 which would possibly remove the divot (not to mention give lots of insurance towards reliable ignition). Also, a smoother transition from hammer surface to cam surface (then polished) would add even more "insurance"!

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks

 

[John E.B. Rawton]

Thanks Mike,
I have been working with the 1851 and after stretching the pawl the full battery lockup is perfect with full cock. I only hear the three clicks associated with the uberti hammer. Half cock, bolt release and fullcock/bolt-cylinder lockup.
I will keep an eye on the lead in ramp to see how the reshaped block works. The cylinder pin has been drilled for a wedge bearing screw. I noticed as I ease into the final clearances, the wedge actually becomes too loose around .007” cylinder clearance.
The cylinder rotation issues (previous pictures) of the 1860 should be cleared up by following the same suggestions. The results are very pleasing.

 

[45 Dragoon]

Great!!
These are in fact "3 clickers" instead of 4!! An adjustable "wedge bearing" is a great asset as far as having your wedge in the proper position to do its job!!

Good job!

Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks