I've been having some sticky PRIMARY extraction with my FN SPR (CRF Win 70 action). Chambered in 284 Win, with a PTG "284 Win Match - no turn" reamer. More on the reamer later.
Load is WW-Super brass, 54.0gr H4831sc, 175smk, Tula primer, 2.950" COAL (tip to tip), goes ~2825fps from a 28" bbl...