That probably has little to do with the sabot seating depth. The Remington Accelerator-line of cartridges has had a bad reputation through the years for inaccuracy. It is most likely more of a speed problem. The combination of the sabot and light bullet are causing the combined projectile to move too quickly down the bore causing the sabot to strip on the rifling. Whether you can adjust the speed to cause the sabot to grip the rifling is questionable.
Quando Omni Flunkus Moritati (If all else fails - play dead!)
Support the Second Amendment. Join the NRA > http://www.nra.org <
Oklahoma State & Big 12 - #1 GO POKES!!!!!