I understand the wizzum was 'designed' to match and not better the Winbag.(factory win loads 2970 vs 2960)... and therefore market the new magnum to those who want the winmag level of performance with a slightly shorter action, because everyone knows than saving 1 tenth of an inch in action length is th different between.... i'll stop there....
But a far as powder burns, in the above 180gr example the max ADI loads are
30-06/180gr/57.5gr/2798 versus 300WSM/180gr/64gr/2950
while comparing the apples, Granny smith versus Pink Lady;
300WSM/180gr/64gr/2950 hottest load, at 63k PSI...
while 300WinMag/180gr loads vary with max from 67 to 81gr, velocities 2916-3042@a leisurely 52k PSI
With the same powder (2209) the max WinMag load is stated to be 67gr at 2918 however at considerably less pressure 53k...