Still catching up on newer powders, so I got a pound of both CFE223 & PP2000 to try in my 700 Classic Whelen per Sierra & Speer's newest manuals. CFE223 worked poorly in my rifle with 200s. Pressure peaked way before Sierra's max loads with absolute max in my rifle barely breaking 2900fps. Accuracy started out mediocre at low charges then became less than lousy at the higher charges, but seemed to be tightening again as the charge got sticky past max. Hoping the PP2000 works better.
Regarding brass... finally out of usable LC67, the new box of Hornady brass was too short for my chamber & developed that ring you see before the case separates on the 1st firing on about 1/2 of the cases, so unfired RP Whelen brass from when Remington brought out the Classic was used,. Sierra used Norma brass, Speer used Federal brass, This could be some of the difference as well as lot to lot of powder variation & 2" of barrel. It's just not worth testing to find out why.
I strongly agree with the above posters about H4895 or RL15 being optimal for speed/accuracy at c.2850fps. So far RL15 is a wee bit more accurate in my rifle but about 35fps slower than H4895 with accuracy loads. IMR 4064 is still a usable but crunchy Whelen powder as is 3031 with 200s. .
