I have no idea why people want to make the .410 shotgun into a capable deer ctg.
We all know a .22 rimfire will take deer with a brain shot but why choose one to hunt deer with when there are so many other weapons that do a much better job.
I've tried the gambit of 12 bore sabot slugs and found them to be at least disappointing and at 3 bucks a shot they break the budgit.
When we shoot .45 bullets from a ,73 bore s.g. we loose the best part of shooting the 12 bore in th 1st place.
The huge bullet!
I have loads for my ultra that use the SPW full bore non discarding sabot that is an honest .73 caliber, gives me one ragged hole at 75 yards, 1450 f.p.s. velocity, and will down any game on this side of the planet.
I think the weapon mentioned by critter has merit.
But! There is no way you could call that modified weapon a .410 s.g.
It's a .41 rifle. That makes it questionable for slug only areas.
Just my 2 cents.