The Colt SAA had 4 distinct clicks when the hammer was pulled in to full cock....
( you also probably know, best to load only 5 rounds so the hammer/ firing pin rested on an empty chamber if dropped it would not discharge)
Uberti/Beretta engineered a rebounding safety hammer ( Ruger uses a hammer sliding bar block ) to allow you to load and carry six holstered. Pietta uses a manual extended cylinder pin setting. ( Uberti did as well and they also had a manual block machined into the hammer )
Purists hate it all , but the lawyers and US customs want the anti-drop feature.
So Uberti has the clever rebounding hammer on most if not all their SAA now. It only has 3 clicks now eliminating I think the step/click in the seer.
It looks the part , it works and it is safe(r) when carry with 6 chambered if accidently dropped.
As I said Ruger and some Pietta ( and the discontinued Beretta Stampede made by Uberti ) use the transfer bar.
( also the discontinued Taurus Gaucho )
You might remember the transfer bar from you Black Hawk ?
As far as I know if you want ( that is
buying new ) the traditional SAA four click/ load 5 for safety
You have 2 choices... Pietta (some not all ) and the $2000 Standard.
Used ? well there are lots of Uberti's, Pietta's or you can spend
big bucks and find a USPFA or USFA revolver
Or there is the REAL deal COLT.
Edit: while I was typing Coffinmaker added his wisdom I hoped he would
to answer his question "
Pietta: Owns and manufactures for
EMF corp. Bought it from the heirs of the late Boyd Davis.
Early and Modern Firearms (EMF) was founded in Los Angeles, CA in 1956 and acquired Great Western Arms Company, the manufacturer of the first reproduction of the famous Colt Model 1873 SAA. In 1971, EMF incorporated and Boyd Davis joined the company. He went on to co-found and became President of Single Action Shooting Society (SASS) in 1981.
EAA imports WEIHRAUCH a German (Mellrichstadt, Germany) manufactured replica ( Transfer Bar hammer block ) they are in...
Rockledge/Cocoa Florida
EAA Corp
PO Box 3008, Cocoa, FL 32924
If I were to buy a new 45 SAA today ...I'd be calling EMF for a Great Western II