The modern cases might have too much base wad volume to work out with your chamber length.
If a proper size ball in a plastic case fits into the chamber you'll likely need a necking die for magtech brass in order to achieve any tension and crimp.
The magtech brass would likely fit your powder charge.

Have you seen the thread on my Purdey 20bore?
It runs the same powder charge. I use Swiss 1-1/2F in specially made cases of similar length as yours.
Works great.