The Hobby Gunsmith

Project - Uberti Regulator

Smoothing the Action

There There are a lot of older single action revolvers to be found at a reasonable price in gun stores or through private purchases. The Hobby Gunsmith had the pleasure of finding two old Uberti Regulator revolvers that had never been fired. The first is a .45 colt and .45 ACP convertible while the other is a .44 special and .44-40 convertible. These older guns have a very stiff action that makes them pretty much unusable as competitive firearms for Cowboy Action Shooting.

The Uberti Regulator on the bench before beginning the modifications.

   This article is about how to take the very stiff and unmodified Uberti Regulator revolver and make it competitive. We will be working with the .44 Special revolver to smooth the action. Before beginning any work, we ordered the Wolff spring kit for the Regulator. The Regulator uses a special spring kit and I have found that the mainspring for the SAA revolver will not work properly in the Uberti Regulator.

   We begin by making sure the gun is not loaded and taking the revolver completely apart to thoroughly clean the insides. We begin by pressing the cylinder pin release and pulling the pin forward to remove it. This will allow the cylinder to be removed out the right side of the frame after opening the loading port.

The Regulator with the rear grip frame and grip removed.  This shows the original hammer spring.

   We then remove the screw at the bottom of the grip frame and then remove the two upper grip frame screws to remove the upper grip frame. With the upper grip frame removed, remove the mainspring screw to release tension on the mainspring and then remove it. With the mainspring removed, remove the two lower grip frame screws from behind the trigger guard and remove the single screw from in front of the trigger guard. This will allow the lower grip frame to be removed out the bottom.

The trigger area reveals the original flat trigger and bolt return spring.

   Look into the exposed area just in front of the trigger and you will see the flat spring that puts tension on the cylinder locking bolt and the trigger. This flat spring is held in place by a single screw. Remove the screw and remove the spring.

   With tension removed from both the hammer and trigger, remove the bolt, trigger, and hammer retaining screws and carefully remove the trigger and cylinder locking bolt out through the bottom of the frame. You should now be able to push the hammer down into the frame and remove the hand (pawl) from the hammer. The hammer can then be removed out the top of the frame. The last item to remove is the extractor housing and assembly by removing the front retaining screw before sliding the assembly forward to remove it.

The hammer, hand, and trigger after being removed through the bottom of the gun.

   Using a gun cleaning solvent, we cleaned all oils from the frame before beginning the inspection process. One of the easiest ways to inspect a gun is to run a cotton swab or q-tip around the machined surfaces to determine if there are machining flaws that need to be polished. Rough areas will snag the cotton and cause fibers to be stuck to the area that needs to be polished. Some of the worst areas were in the hand channel that was poorly machined on the project Regulator.

   We began by using the hard and fine Arkansas stone to polish the insides of the frame where the hammer rubs during its swing. The purpose is to remove any roughness, but is not intended to change the dimensions of the gun parts. We lubricated the stone with unscented mineral spirits and polished until the metal was smooth. It was not necessary to remove the bluing on the inside of the frame, but the high spots of the machining did become polished to a bright silver of polished metal.  

   We used the stone to polish the sides of the hammer to remove a few high spots that might create friction against the newly polished inside of the frame. We used a little 600 grit wet or dry sandpaper, lubricated with mineral spirits, to polish the inside of the hammer screw hole and we polished the rubbing surface of the hammer screw. This removed a significant amount of friction from the operation of the hammer.

This photo shows the roughness encountered down in the hand channel.

   We moved to the hand channel and used the stones to enter and polish any raised surfaces. There were several transitional areas where we had to use a small file to remove the excessive amounts of metal from questionable machining.

   Both the hand and the bolt were very rough so we spent a lot of time polishing these parts. The hand makes a lot of contact on three sides of the opening so we polished each side of the hand and the bottom side, which is opposite the spring side of the hand. Polishing with the Arkansas stone gave a better appearance, but we did not attempt to remove any material, but just flattened the high areas of the original machining to reduce friction.

   The Uberti Regulator has a cylinder with an arbor bushing and a gas check. The gas check is the small extension on the front of the bushing that diverts gasses away from the cylinder pin to prevent fouling. We removed the bushing by forcing it out the front of the cylinder and polished the surfaces between the inside of the cylinder and with the cylinder pin. We also polished the inside of the cylinder where the bushing slides and we polished the cylinder pin itself.

The revolver cylinder with the polished bushing slid forward exposing the gas ring.  The retaining pin is below the cylinder.

   Polishing the bushing made a tremendous difference in the smoothness of this gun. In fact, it made the cylinder spin too smoothly and it began to over rotate while the gun is being cocked. Over rotation is when the hammer is pulled back and the hand pushes on the star at the end of the cylinder and the rotation moves so quickly the cylinder locking bolt is unable to move quickly enough to lock the cylinder before the bolt recess passes the locking bolt and the cylinder stops out of battery.

The original condition of the sear, sear ramps, and the cylinder bolt locking cam.

   This condition will make the gun sensitive to the amount of force used to cock the hammer, and should be corrected. We tried using a stronger cylinder locking bolt spring in an attempt to force the bolt into place more quickly, but this failed to have any affect, because the bolt was being released too late to grab the cylinder and stop its rotation.


The modified cylinder bolt locking cam.

   The cylinder bolt cam is located on the right side of the hammer and determines the release of the cylinder-locking bolt and the timing of the gun. As the hammer is cocked, the cam contacts a finger on the cylinder locking bolt and raises the end of the bolt, which lowers the other end of the bolt, which releases the cylinder to rotate. As the hammer reaches the rear of its travel, the cam releases the locking bolt, which enables it to lock the cylinder into the proper battery position. This cam needs to be adjusted on our project gun to allow the cylinder-locking bolt to come up earlier to engage the cylinder locks.




The finished and polished hammer showing the modified cam, the polished sear, and the polished ramps.

   Adjusting the timing of a revolver should be done carefully. On the Regulator, a flat area of the cam determines when the bolt will be pulled away from the cylinder and when it is released to return and lock the cylinder.

   We decided to remove a little metal from each end of the flat of the cam to hold the cylinder while the hand is moving forward and to release the hand early in the ramp that guides the bolt into the lock. This was done using a flat disk on a rotary grinder to slightly adjust the ramps of the cam. We made only very slight cuts on the cam before testing. This was to prevent us from removing too much metal as it is difficult to put metal back on once it has been removed. When we were satisfied the cam timing was what we were looking for, we polished the areas of the cam where we had ground metal away.

   The trigger sear of the Regulator was quite high, which gave us a trigger with a lot of creep prior to the release We used a hand stone to remove quite a bit of metal to bring the sear down to a height of about .030 inches. This gave us a good engagement and we polished all of the ramps with the Arkansas stone. We maintained the original angles on the sear to prevent creating a trigger that might slip from the sear and allow the gun to unintentionally fire.

   Springs are a common part of an action job and we ordered a complete set of Wolff springs for the Regulator. We could have used the springs for a Colt SAA revolver, but Wolff sells a separate kit designed specifically for the Regulator and we chose to use the springs specifically designed for our revolver. We installed their wire trigger and cylinder locking bolt return springs along with the lightened mainspring.

   The handspring is a weak area in the SAA clones. We would like to see the spring makerís supply better contoured and lighter replacement handsprings, but none seem to provide these critical springs. We have successfully adjusted factory handsprings to provide less force on the hand while maintaining enough force to put the hand into contact with the star on the end of the cylinder.

   We carefully made slight bends in the spring to reduce the force on the hand. It is important to consider that no single part of the spring can be bent very much. We selected a section in a larger radius and bent the spring to a slightly lower radius by bending the spring just a little beyond its memory so it would return to just a little different position. We did this along several areas until the hand was pushed forward toward the cylinder, but did not require a lot of force (and friction) to put it into place.

   With all of the springs adjusted and the rubbing surfaces cleaned, polished, and oiled, we assembled the gun for a final test. We had tested the components as we worked on them, but this was the first time we completely assembled the gun for testing. We were very happy with the new feel of this old Uberti Regulator. The hammer glides back into place with so little resistance we suspected it might not be able to fire a primer. The trigger break was smooth, crisp, and clean.

   With such a smooth and lightened action, we were worried that the hammer was not falling with enough force to ignite the primers. We primed some empty .44 Special cases and all ten primers fired without problems. We tested the action by rapidly cocking the hammer as we would in a match and the gun locked up properly each time.

   We took the gun to the next monthly cowboy action match at the Mother Lode Shootists Society to test it in competition. The gun fired reliably and accurately for the three stages we used it and we are very satisfied with the work we have done to bring this old gun back to life.