Here's some clues for the witless who take an innocent faith in bunches of printed data:
There is ONLY case volume and pressure.There is no magic in case design as far as velocity is concerned.Pressure is affected by a variety of factors; among them are barrel internal dimensions,finish,smoothness,barrel length,condition,throat and leade length and configuration,groove diameter,and we won't even get into variations in bullets and powders along with powder energy, primers and how you hold your jaw that day.
Just because you are loading to "SAAMI" tested data from another barrel does not mean you are safe and running at the same presures.Conversely, just because you are loading powder charges in excess of manual data does not always mean you are "unsafe" or loading to excessive pressures or in excess of SAMMI spec.
What this means is that unless you box up your rifles and loads and ship them to a ballistic lab(the way that guys like Warren Page, and Bob Chatfield-Taylor used to do in the days before home chronographs),or buy an Oehler or other spressure system for home use, you have no idea at what pressures you are operating,due to the many variable factors cited above.
You are only left with velocity readings,outward signs of presures and traditional pressure signs,a broad range of data,and velocity readings from your chronograph.(Note the language at the bottom of the load data that nsaqam posted: "if possible, measure the velocity and correlate with our data..." what do we suppose he means by that?
BTW in looking at that data,it looks normal and about what I would expect from a 280AI....(not some of the excessive speeds I see listed by some on this forum,which are so clearly off the charts I have to wonder at the stupidity of it all)...a 7 Rem mag with a 24" barrel will easily hit and exceed those velocities.
So, when I see some one get on here and proclaim to the world that velocities for a smaller cartridge equal or exceed those of a larger cartridge and "claim" that their loads are within SAAMI specs because he is using "proven" data, I am not only skeptical; I know for sure something is not equal across the board.
Another thing that anyone with any experience realizes is that with light bullets a slightly smaller cartridge will come "close" to a larger cartridge with the lighter bullets if you kick it in the ass hard enough....but will never come close with the heavy bullets.
So when I see velocities quoted for a 280AI with a 140 gr bullet that equal those of a 7STW,or those for a a 160 gr bullet that I know is about maxed out for a 7 Rem Mag with safe but top end loads(after seeing piles of them at work),and listen to them trot out a bunch of printed data and quote QL as "backup" established in other barrels,I know they are FOS and clueless.
They cannot possibly "know" unless their loads were pressure tested in their rifles with those components.
