I've never tried any of the gauge mates. Bought one of the Savage .410'ers real cheap at a gun show a long time ago. Shot a few shels from it & boxed it back up, it's still on the shelf somewhere. As I recall is was about 9" long, had steel chamber & aluminum barrel & fit a 16 gauge. Added around a half pound to the gun. Too easy to load a 16 down to 3/4 oz of shot with out throwing the gun out of balance & better patterns also to fool with them 'Dapters in My Opinion.
Most of my "Welded" barrel guns over the years have been 12's & I mostly use 1 oz in them though have loaded heavier at mild velocities & pressure, but I don't fool with those Super low pressures, if a gun won't take around 8K its a wall hanger as far as I'm concerned. Cold weather squibs taught me my lesson on that out in a duck swamp back when lead was still legal fodder.
Being somewhat of the Lazy sort I do most often load smokeless for my Damascus or Twist barrels as clean-up is so much "Cleaner" & easier.
