Ted , I think you are misinterpreting what it's saying.The interpretation provided to me was that the Proof Load must generate at least 30% more than Service pressure at both the 17-25 mm (Peak or max chamber pressure) and maintain that 30% overage to a point of 162mm (6&3/8th Inch). Maximum 2& 3/4" load
service pressure at this 6.4" point was 1.8 tons PSI lead crusher,4030 psi lead giving a proof cartridge requirement of 5250 psi lead at 6.4" they do not in fact have two different loads. one load fired twice that meets both chamber and 6" requirement
Hope this helps clarify.
