I have been shooting the 260 for years and absolutely love it. It is mild mannered, easy to get accurate loads for, and very accurate. Brass is easy to source like Tactical Teacher already said, and there is a multitude of factory head stamped brass available as well. I use Lapua brass and Lapua 136 Scenar bullets for my LR loads, CCI BR primers and H4831SC--but I am going to try some H4350 because those speeds that Skullboy is getting are awesome, my current loads are about 100fps slower. I have never played with the lighter Scenar bullets in my 260s, but the results that Tactical Teacher gets are impressive and I may have to give them a go sometime soon.
There is not even a little tiny hairs difference between it and the 6.5CM, I have one of those too, and while it is a great shooter I will run my 260 all day before I grab the CM. The old 6.5 Swede is a sweetheart of a round too, and as others have said, it has killed a LOT of moose and other big game in Europe and it is essentially the ballistic twin to our favoured 260 here in N.A.