No offense, but IMHO, even the max loading in those recipes appear to be driven by "Corporate Liability Lawyers". I'm not reckless like Tim was but those are some wimpy loads, even in my AR platform.
Not trying to encourage members to go off the deep end WRT safety, just comparing them to my own experience with the 275 XPB. FWIW, unless you have a real long (≥ 24 inch) barrel, CFE BLK is a joke with a 275gr bullet in this caliber. It's slower than AA1680! Not sure why that made the cut. With the popular 16 inch "pop-gun" barrels, it would be less work to just bring the CFE BLK bottle to the range and throw 1/4 of it on the ground unburned!
Hoot