Ive shot a version of the PR called a QT in 45x40-250gr, sold under the Cabelas Extended Range label....same bullets/sabots. Basically a blue tipped Dead Center.

I found it to be a pretty good shooter with 100gr of Bh209 but that seemed to be the only load that grouped well. It was good for about 1950fps MV and repeatable 1 3/4-2" 100 yard groups.