Postino and John
Yes,the frame of the Mitchell is a casting,while the cannon assembly is mostly a machined forging.

Very similar in manufacture to my very early stainless steel 45 AMT Hardballer .

Although I think the AMT has harder metal,as I have noticed no deformation on the frame.It does have galling problems without the correct lubrication,however. The metal on the AMT is also more brittle as I have friends who have cracked their AMT's slides by heavy use.

I guess it is a trade off.
Bob