Have a Uberti 1885 Low Wall copy . My question is with the main spring that rides between the breech block . There is a slotted screw on the left side that fits between the main spring . The other end of the screw is just flat . Is this a threaded deal ? I can turn and turn both clockwise and counter and no loosening or tightening is noted . Is this just a pin with a srew slot on one side ? Thanks .

Brudfored, I believe you are looking at the Hammer pivot pin. It goes thru the breech block and the spring has nothing to do with it. The Pin is a split pin nearly all the way to the far side with the plain face. In use with the breech block out of the rifle you park the breech block on a flat surface with a hole big enough for clearance of the pin and tap it out thru the breech block. You tap on the split side, the split will compress and let the pin go thru. HTH. Not sure if Uberti uses the Flat spring system or the coil spring system. Do not attempt to remove this Pin without disassembling the action. It is meant to be removed as a secondary disassembly to deal with breech block, or hammer issues. HTH. Regards, FITZ.

Brudford, to re-state: what you are looking at is not a screwdriver slot, but the head end of a SPLIT pin that's heat treated like a spring.  When a pin punch is placed on the end with the "slot" or split, and a hammer is used to strike the punch, it will spring inward and allow the head on the split end to enter the hole in the breechblock.  It can then be pushed through the block and hammer to allow the hammer to be removed.  Take a look at the wooden clothes pins in this illustration:  (You need to Login or Register to view media files and links); The hammer pin works the same way.

David

Brudford, Horay! now you got it. Once you have taken a Model 1885 apart "All becomes Obvious" Good luck in the future. Regards, FITZ.