The magtech brass has very thin walls - which can complicate matters if used in place of paper or plastic (thick walled) cases in chambers cut for the thick walled case. Getting them to size properly on proper projectiles can be tricky - if the gun isn't set up for the thin case.

This is why I say to cast and measure the chambers and bores of the tubes.
Paradox guns want projectiles right at cylinder bore diameter, measured before the chokes.