Don't hear much here on the AMT Hardballer....
I think now the company is (was?) IMI or something like that now. Are these folks still around?
They made a M1911A1 that was as rugged as a Sherman tank at one time. Never owned one myself, but a friend of min had the Hardballer and a Long Slide, both in .45ACP. The Hardballer accounted for a number of groundhog from thirty to seventy-five yards.
Autopsy of one shot end-to-end with 185gr. Sierra JHC revealed classic hollow-point performance.
With the exception of being stainless steel, these seemed to be fine pistols.