Im at work so i dont have any manuals handy. i have No dog in this fight but Noslers online data was easiest to find fast. Surprised what I found.
Nosler actually shows the .280 A.I as fast or faster then the 7RM for 120, 140,and 150's. Pretty much even on the 160's and slight advantage to 7RM in 175's.
Granted the 280 AI data is for a 26" barrel and the 7RM a 24" but the 7RM was using more powder most of the time.
I'm not the smartest man and would have sworn the 7RM would have had a bigger advantage but according to that data and the Saami map they aren't far apart.
As said above I don't have my own pressure barrel but I'm making the assumption that Nosler isn't leaving much on the table when it comes to Saami specs.
I've never went above Max book in any of my rifles and dont see a need to. I typically am shooting close to max if no pressure shows in my rifles, but i wouldnt say i "hotrod" any of them. Some rifles shoot faster then others which is a given but assuming people are hotrodding their .280 AI to get close to 7RM while following Saami is a stretch. The data shows they are very damn close with same barrel length and loads. 100-150 fps isn't much to me when the bullet is well over 3k.
Yes I shoot the 140 TTSX at Barnes posted max but in my gun the primers aren't flattened, bolt lift is easy, no signs of brass stretching or other pressure signs that the common shooter can see. 62 gr of R22 in a 24" tube gets me 3315fps, takes 65 grs IIRC to do that in my 7RM with its 26" tube and it doesn't like that load for accuracy.
I also have owned a .270 which got its 140's to 3050fps with a 24" tube and book max loads which iirc was close to 56 grs. So I'm shooting 6 more grains of powder for 265fps more.
Long way of saying there really isn't that much difference if barrel lengths are same and Saami map is followed.
