The main question is barrel thickness that is needed
for our slower powder loads. The loads don't have any more peak
pressure than magnum factory slug loads(like Federal),
but the longer taller pressure curve that goes with slower powder
might rupture the barrels on most doubles. Unless each barrel is
like on heavy barrel NEF Ultras. I have 10ga Zabala double and
after measuringmuzzles I figured it wasn't safe for slow powders.
Barrel should be 1.050" at muzzle for 10 ga with our loads.Ed