RE: remington accu tip slugs
The Accutip slugs were made specifically to shoot out of a rifled barrel. If you try to shoot them from a smoothbore then you will have the same issues as shooting any other sabot slug from a smoothbore
From Remingtons site:
Premier® AccuTip Bonded Sabot Slug
Power Port™ Tip delivers dramatically superior accuracy
Spiral nose cuts and proprietary bonding technology control expansion at all ranges from 5 to 200 yards
Huge .58-caliber slug is the largest tipped slug available today
Over 95% weight retention – weighs more after impact than all the others start with!
Slug jacket made from high-strength cartridge brass
Designed for use in fully-rifled barrels only