I did mine on a face plate, with a thick block with a mandral drilled through, welded on the backside and bolted to the face plate. I then turned the taper to matck the chamber and made a clamp going from two studs out of the plate with a bar across the underlumps.

It is on the thread which is in the archive somewhere.

This is also a Zabala, but in this case a 3 1/2" mag.

NB Make sure that you hone the chamber and bore out first. It is hard chrome plated, I dident find out until I was ready to solder up. That was not the best time !!!

Regards