444,
Your Herters is indeed a .44 Magnum. (read below)
And you are correct as to why the Single-Six name was struck through.
Ruger had previously trademarked the name Single-Six.
All of the Herter's guns I have seen were identical to one of the Hawes models. I believe both lines were made by J.P. Sauer.
Gargoyle,
Back in the early 1970's I bought a used Herters .401 Powermag. I loved it. I thought it was a great gun/cartridge combo. But only Herters sold ammo for it. Shortly after I bought mine Herter's announced they had discontinued production of the ammunition so I ordered 250 rounds. A few months later they sent me a letter saying, since there would be no more ammunition available, that if I sent them my .401 they would send me a .44 Magnum.
A couple of months later, after I had used up all of my .401 ammo, I sent it back to them. What I recieved back was the very same revolver I had sent them only fitted with a new cylinder and barrel. Serial number, as well as all of the scratches and dings, was exactly the same.
This is why there are so few .401 Powermag revolvers left.
But, just like the one 444 has, no where was the word magnum used on the gun itself. On the box there was a new label stating that it was a .44 Magnum pasted over the original label.
Mine was the only Herters .44 that I ever saw thay didn't say magnum.
So I wonder if the one 444 has, is one of the converted .401 models?
With all of the bullets available now for the .40S&W and 10mm the .401 Powermag should now be a handloaders dream. (If you could only find the brass.)