Well, Driftwood, I'm not talking about just drawing the hammer back to that first click. Do that and you can still pull the trigger and drop the hammer. The "safety" I'm talking about is much more positive than that and the trigger is locked so it can't be pulled. But the very reason you mentioned is why I have "safety" in quotes. Strike the hammer hard enough and likely something in the mechanism will break and the gun could still fire. But it's still a lot safer than having the firing pin resting on a primer or the hammer just sitting in that first-click notch. The dude in this video is talking about what I'm talking about at about 8:04 where he loads all 6, pulls the hammer all the way back then slowly lets it down until he hears the first click then releases the trigger and lets it down the rest of the way. This is totally different from letting the hammer down and then pulling it back into that first click.
Oh my goodness, where to start?
If you listen to the guy in that video, he clearly states the Smokewagon he is holding has a hammer block built into the hammer. The hammer block he is talking about is the same one in this grainy photo I posted earlier. You can see the part of the hammer block mechanism just below the firing pin. So yes, for Uberti hammers equipped with that hammer block you can load six into the chamber. I used to have an Uberti Cattleman with this hammer block built into the hammer. To tell you the truth, despite what the video says, and what the owner's manual says, I would not trust it. I remember how tiny the parts were and if you dropped the gun on its hammer, chances are something might break.
Well, Driftwood, I'm not talking about just drawing the hammer back to that first click. Do that and you can still pull the trigger and drop the hammer.
That is simply incorrect. I don't know any more subtle way to say it.
Let's take a look at some Colt parts. Uberti Cattleman parts without the built in hammer block are basically the same. There are two arrows in the photo. One is pointing to the tip of the trigger, which is called the sear. The other arrow is pointing to the so called 'safety cock' notch on the hammer. When you pull the hammer back to the first click, the sear drops into that first notch. Notice there is an overhanging lip on the notch that traps the sear. If you try to pull the trigger while the sear is in that first notch, you cannot pull the trigger, the sear is trapped. The hammer will not drop. If the hammer drops, something is broken. Now notice how thin the sear is. And notice how fragile the overhanging lip on the 'safety cock' notch is, as well as the overhanging lip on the next notch, the half cock notch.
If you squeeze the trigger hard enough with the sear trapped in the 'safety cock' notch, you can break the lip right off. In that case, the hammer will drop if you pull the trigger from the 'safety cock' notch. By squeezing the trigger very hard you might instead snap the sear off the trigger, ruining the trigger. Same thing with the half cock notch.
Generations of single action revolver shooters have known that the so called 'safety cock' notch on the hammer of a Colt, or an Uberti, is not a reliable safety. Keep a live round under the hammer, with the sear trapped in the 'safety cock' notch, and drop the gun on its hammer, and one of those fragile parts is likely to break, discharging the firearm. Its even been known to happen when a cowboy slung the stirrup of his saddle down and the stirrup struck the hammer. Heavy enough of a blow to fire the gun and send a round into the cowboy's leg.
It could happen with the old Ruger Three Screw single action revolvers too. Even though all the leaf springs had been replaced by coil springs, they still had the same three notches on the hammer. I remember reading an article by Mike Venturino years ago where he stated he arrived at a local range to find a man lying on his back, covered in blood. The man had been shooting an old Three Screw Ruger, and it had discharged when he dropped it. The man died before they got him to the hospital.
Here is the hammer from an old Three Screw Blackhawk. Look carefully and you can see the over hanging lips on the 'safety cock' notch and the half cock notch. They are just as fragile as the overhanging lips on the notches of the Colt hammer. That's why Ruger discontinued making the Three Screw Blackhawks in the 1970s and completely redesigned the mechanism to include a Transfer Bar. A Ruger equipped with a Transfer Bar is safe to carry completely loaded with six rounds. Drop it on its hammer and nothing happens because the Transfer Bar is not in position to transfer the blow from the hammer to the firing pin.