I have one that I don't shoot very much but it functions surprising well and never jammed or had a stoppage.
And I found a bunch of mag.'s on eBay back when I wanted them.
I just saw a new factory mag. for sale at a gunshow last month.
I didn't need it, but they're findable.
I just wasn't very happy with the AMT's accuracy. I found some rounds online with lighter weight bullets to try but I never did buy any.
I also have an Automag II .22 Mag. and it functions great and also has excellent accuracy.
I'm sure that some AMT's have function problems, but certainly not all.
On the other hand, when I had a new Ruger Blackhawk .30 Carbine, I had one of the reportedly few where the tapered .30 carbine round would keep backing out of the chamber which would cause a jam by preventing the cylinder from rotating. That would never have been acceptable for any kind of reliable self-defense weapon, so that was one gun that I ditched at a loss.
So make that +2 for AMT and -2 for Ruger (Since now I have another Ruger revolver that needs to go back to the factory for a cylinder fitting problem).
I'll bet that the Taurus Raging Thirty revolver with moon clips is much more reliable than the Blackhawk, even though they say that a moon clip filled with .30 carbine ammo is like loading strings of spaghetti into the cylinder.