I haven't tried CFE223. I have been playing around with Varget, IMR 4320, and H4895 in my M700.
Reeds Ammo and Blackhole Bullets are your best bet currently if you are looking for 17 cal heavies. I just got some of the 25 gr VLD and 26 gr VLD bt from Reeds last week but haven't loaded any yet. They appear to be very high quality pills.
It's good to hear that you're developing some 17 cal pills Steve. It's a niche market with a dedicated following for sure.