Historically Unsafe?

The venerable, and multi-named, Colt Single-Action Army, Peacemaker, M1873 has a safety flaw.

It's common to nearly all revolvers of its era, so it's completely forgivable.

The firing pin is attached to the hammer in a manner that makes it unsafe to carry with six rounds in the cylinder.

Kind of makes calling it a "six-shooter" something of a lie when you can only load five and have the hammer down on an empty cylinder.

Armi San Marco and Pietta went with an extended cylinder pin with two detents in it.

You push the cylinder pin release and then press the cylinder pin to the rear where it will intrude into the hammer recess and prevent the hammer from falling all the way to the primer.

Cylinder pin intruding...

...No firing pin intruding.

No cylinder pin intruding...

...Firing pin intruding.

It's awkward and irritating to use.  Especially so with the Pietta version where there's just a single groove in the cylinder pin which must be perfectly aligned with the cylinder pin release.  The Armi San Marco version has the groove running 360° around the cylinder pin.

It's not realistic to expect someone to use this as a means to carry six rounds safely and most likely exists only to allow importation from Italy with a historically correct firing pin.  This system also retains period correct guts which has the proper 4-clicks.

Uberti has taken a different path.

Their firing pin floats.

Firing pin to the rear.

Firing pin foward.

Uberti has a linkage up inside the hammer which presses the firing pin forward when the trigger is being held.

Holding the trigger.

Trigger released.

It's not spring loaded, so it will not retract unless you press the firing pin's nose or let gravity pull it down.

This is a lot more practical, but...  The lockwork isn't normal SAA and it only has THREE clicks!

Abomination!