Well for one, those calculations were made using LOAD From A Disk, not QL.

Second, the calculations are "conservative" numbers, a guide if you will, not necessarily the max velocity-pressures (SAAMI or otherwise) for a given cartridge. The reason? There are too many variables, things such as the case internal capacities manufacturer to manufacturer, the bullet seating depth off, on or in the lands, barrel, powder lot numbers and etc. Also, unless one has the equipment to measure pressures for a load is a WAG at best.

Bill