Here is picture of the 12ga wad column using two
BPI BPGS seals, Flexseal,cork, and sabot. Bret in
MN has, in a long heavy rifled barreled Savage
like mine, gotten 28-3000 fps with a 500 gr XTP bullet
in the sabot with a 3.5" plastic case. And it extracts
ok with the Savage bolt action extractor.
He is using slow shotgun powder, Alliant Steel.I can't
get that high in my NEF 12GA FH and make the
extractor work with the Alliant Steel powder loads.
The NEF handles pressures fine, just doesn't extract
like a bolt action Savage 210. Using RE17 without cork,
I get 28-2900, with max of much slower RE17 with 420gr
slug in the sabot, in NEF The case shown was fired with the
RE17 load like that....Ed