I talked to a guy in SA who has a youtube channel, and he and his buddy shoot 260 Rem.  He swears he's getting 3K fps with 130 gr Berger VLD hunters with no signs of over-pressure.  The 6.5 tapers more (wider at base, narrower at the bottom of the shoulder) than a 308 Win case, but it is 4 mm longer.  If he's really getting 3K fps (Tikka T3 Varmint), I wonder if he really knows what signs of over-pressure actually look like.
These guys have some interesting loads for 6.5x55SE:  
http://www.realguns.com/loads/655mmswede.htm.  Their published velocities don't quite jive with IRL experience of another guy on this board (I'll let him announce if he wants). 
I worked some 143 gr ELD-X/IMR-4831 loads up, to a little past hornady's published max, and shot them yesterday (Tikka T3 hunter).  Been sort of busy since I got home from the range yesterday, but I'll put my calipers to the over-boosted brass and check the deltas between factory hornady brass and the other within-normal-limits loads I worked on.  I'll let you guys know, but I don't expect to see anything unusual.  Extraction certainly felt like the other brass, and there was no primer deformation or any other obvious indicators of over-pressure.