I'll be a bit nice when I hold my tongue enough so that all I say is, "Where did you get your information"?
the Nosler #6 manual lists the fastest velocity with a 180gr bullet for a SUAM being generated with IMR 4831. The charge is 8.5gr more than a what is used in a 30-06. There is about a 250fps difference in those loads.
However RL22 takes "only" 5 more gr in a SAUM to gain a whopping 30fps difference.
The fastest loads for these two cartridges are about 150fps difference (with different powders) but there is still quite a variance in charge weights. When you drop the charge weights in the SUAM to match what you can put in an 06 case, then the 06 is about 200 fps faster.
If you do the math, the SAUM is faster, but NOT more efficient than a 30-06.
My data list a 300 saum w/180 grain bullet moving 2900fps w/ a 55 grain charge of IMR 4064 vs the average charge in my data to push a 30-06 w/180 grainer was 55 grains at 2700fps both barrels were 24" My data also list 3 lighter charge weights for the 300 SAUM pushing a 190 grain bullet at 2700 fps then any pulished 06' data I have.