It is marked "7MM EXP REM 280 REM".
Winchester/USRA has chambered the 280 in a couple different Model 70 configurations, but I think that they were all marked "280 REM". Since my .284" bore cartridges of choice have always been the 7x57 and 284, I never got excited by the 280. More recently, I have been shooting the 7mm SAUM and think that it is a nice cartridge that, I am told by reliable sources, is just a short action 280AI, performance wise.
JEff
