You simply will not fit a PRC case into the WSSM action. The PRC case is 2.030 (51.5mm) long, the WSSM is 1.67 (42.4mm) long. Whilst they share the same case head dia., the extra length precludes actions designed for the WSSM from taking a PRC case.
You could rebarrel to 6.5 WSSM which would give performance similar to a 260 Rem or 6.5 Creed.
My personal favourite for these actions is to go up in calibre to 405 and chamber for a 400 WSSM. Same bullets as the 405 Winchester or 450/400 Nitro, similar performance at the muzzle and on critters too.