Uberti revolvers can be found with one of two safety systems and a few have both.
If you pull the cylinder pin out, you will see two grooves at the front of the cylinder pin.
The groove closest to the forward end of the cylinder pin will act as a hammer drop prevention when the cylinder pin is pushed into the frame far enough for the cylinder pin retainer to contact this groove.
Pulling the cylinder pin out until the second groove contacts the cylinder pin retainer will allow the gun to fire.
What happens when the first groove is in contact with the cylinder pin retainer is the back end of the cylinder pin extends through the rear of the frame and prevents the firing pin from contacting a primed cartridge by arresting the full drop of the hammer.
This is effective but if the gun is dry fired and the hammer hits the cylinder pin too many times it will cause the rear end of the cylinder pin to mushroom making it all but impossible to remove the cylinder pin from the gun or even pull it far enough forward to make the gun fire.
This dry firing willl also distort and mar the front of the hammer, so don't dry fire the gun.
Even with the cylinder pin pulled forward to the fire position, don't dry fire the gun, use snap caps.
The second safety system Uberti uses is a hammer mounted block.
You may notice a mechanism on the front of the hammer and a little headless turn screw on the side of the hammer.
Turning the screw clockwise causes the mechanism to advance up and out of the front of the hammer.
This again acts as a block to prevent the firing pin from contacting a primed cartridge and again, dry firing will damage this mechanism as well as the hammer groove in the rear of the frame so don't do it.
Turning the screw anti clockwise will lower the hammer block mechanism and allow the gun to fire.
As I said, some guns will have the cylinder pin safety, some will have the hammer mounted blocking safety, and some guns will have both. HTH
