Similar names, different guns
A slight correction in terms is needed, because while the names are similar, the guns are very different.
The Auto Mag pistol (note, two words) was made by Auto Mag (not AMT), and after the original company went under, it was made by TDE until they went under, and then Hi Standard produced a very small number of guns before dropping the project.
AMT is Arcadia Machine & Tool and they produced the Automag (one word) pistols. Their guns were Automag II (.22WMR), Automag III (.30 carbine), Automag IV (.45Win Mag and 9mm Win Mag) and the Automag V (.50AE)
The AMT Automags are very different pistols from the original Auto Mag design. The AMT guns (other than the Automag II, which is a delayed blowback) use variations of the Browing tilt barrel lockup system. They have slides. The original Auto Mags, and the new Auto Mag in this thread use a multiple lug rotating bolt lockup, and don't have slides like most semi autos.
The .44AMP is easier to shoot than the .44 Mag revolver. Part of that is the much different grip shape, and part of that is that the Auto Mag is considerably heavier than most revolvers.
Harry Sanford was the "main man" behind the original Auto Mag company, and was hired by TDE to run its production of Auto Mag guns as well. After that, he went to work for AMT. Other than that, and the name sounding the same, but spelled differently, that's the only connection I know of between the original Auto Mags and AMT's Automag pistols.