In my opinion it fails when the OP is trying to compare both cartridges in terms of performance, because the 270 W is working at a (almost) magnum pressure level while the 6,5 x 55 SE on the other hand is very moderate regarding this. The 270 W simply plays in another class, and while it can deliver a 150gr bullet over a long distance with ease and more than enough terminal energy and with flat trajectory additionally, the 6,5 x 55 is beginning to gasp. Here in Scandinavia or in Germany we have (old) legal rules that are demanding at least 2000 J of terminal energy at a 100 m if you want to hunt deer sized game or bigger. Minimum bullet weight is 139gr / 9 grams. Factory loads for the 6,5 x 55 aren't getting this done ... so manufacturers have to go up with bullet weight like 156gr, 10,1 grams. Ok, those bullet - cartridge combinations get the job done, but forget about long - range hunting! Not further out than 200 m please! The 6,5 x 55 is a very accurate, low recoiling rifle, but it has its clear limitations. A 6,5 - 284 could fill the bill though.