Some reloading manuals,well most of them will have different results with powders listed. Some are shot in different lenght barrels as there test results,and all are shot in different conditiions. One main thought also,as manuals just being a guide,not written in granite,is that older manuals will have a real difference in stats! Some of there old starting loads are max loads now days.The reason is liability law suits,that our community of lawyers has created. Always check with one or more manuals to double check the loads you want to use. vangunsmith