Corey,
100 yards.
txhunter58,
This method is for the sharp crowns on Knight Disc Extreme rifles, not for the rifles with QLA's. My NEF Huntsman has a "relieved crown" (for lack of a better word) where the bullet has the oportunity to sit slightly inside the bore allowing it to swage the rifling. The Knight lands (.5015) and the flare on the base of the FPB (.507) have a conflict when starting the projectile, and therefore must be started perfectly straight for best results. After pre-rifling the bullets, you just line up the kerfs with the lands, they fit perfectly. The flare is only about .125" from the base, and that will be the only part that ends up pre-rifled.
Cajun,
No need to pre-size/pre-rifle for any rifle with a false muzzle, that QLA keeps things lined up. It would probably hurt accuracy unless you get the rifling kerfs lined up. This is for the sharply crowned rifles, the Knight had much better accuracy. I don't think I could ask for better accuracy out of the NEF Huntsman, this was not the standard breech plug in the NEF, it is a custom 209 plug. The standard plug will not seal well enough with the primer carriers using BH209.