I will bet that White 451 1-20 will shoot a 40cal 200gr or larger in sabots very well. Those larger PRs QTs should be about perfect. IIRC those did very well in competition in a fast twist 45cal.
Did White offer a sabotted PowerStar for the 451s? I thought they had something that looked like the PR Extremes but maybe heavier. Ive got some Miester cast .401 260gr RNFPs if you ever want some cheap ones to try out.