Did you try any powerbelts before you started shooting sabots? I always fire a package of powerbelts out of any new gun before I start accuracy testing. I just feel it helps the bore break in some.
Groups fired from Disc Extreme from Left to right. 260 Platinum tip/HPH 12 sabot, 200 SST/Shockwave/MMP Blue sabot, and 195 gr. Barnes/MMP Blue sabot. All fired with 100 gr of Triple Seven. Left most target, group to the right measured 1 1/8" CTC. The left group did 1" on the nose. The other targets were new projectile tests.