Re: 6-284 ?
My dad has a 12 twist in one of his and can shoot up to the 90gr B-tip in that rifle. The other one he has is a 10 twist which he is planing on using the 95 Berger or 95 B-tip in. If it was me I would go with a 9 twist and shoot the 80gr Berger or 87gr V-max. If you want to go lighter than that a 70gr B-tip will handle the 9 twist well also. The 6-284 shoots very flat with just about any bullet you feed it just depends on what you want out of it. My dad's 12 twist rifle has a 25inch K&P Barrel and he was pushing the 80gr Berger at 3720fps and that load really smokes a yote at 500 yards.
Fast, Flat, and Accurate