Some info we have found out about the operation of discarding sabots.
In first picture you see thin white line between the strong powder
and the sabot. It is the white fiber cushion wad pressed flat. It is
shown on the left in second picture. In the picture of it compressed
you see it is pushing squarely on the sabot. This is most important
wheh the sabot and slug exit barrel to get the slug started as
straight as possible for accuracy.

Other types of plastic cushions aid in sealing and help get best
velocities but the rolls and legs in them can allow them to side shift
which can affect how straight the sabot is on exit, thus causing the
slug to deviate. The gray sabots we tried had cushion on the bottom
of them and inspecting them after firing you could see they were pushed
sideway some of the time. That is why we are trying to get tight
fitting simple sabots built and recommend using heavy plastic seals
with fiber wads to have least deviation and best accuracy.

Third picture is our steel block we are using for 2bore
with breach hole we got EDM'd into it.

Fourth picture is an old time Kynoch round called the
"Lethal" and the "destructor".

Fith picture is a H&H underlever double 8bore.
Nice beautifal old gun.Ed