There is such a round as a 6.5x55 AI...it gives 100-150 over like a 6.5x284 IIRC. Should be w/in reach. I'd seriously not sweat some fps...just me.
Bear in mind, ALOT of 55 data, was meant for 1894/1896 Mausers...though they were IIRC Proofed to about 67K...but may be CUP. I'd never 'hot rod' a mil-surp, as I had a near mishap about 18 yrs ago...re-formed brass, no neck turning i.e. crimped...blown case...cracked bolt threads around the striker that could have went thru my head.
ONLY load in a Ruger, Rem, Win, Sako, T3, etc. - MODERN loads for Modern rifles IMHO.
But, to answer, a 140 at 2600 is good for 300-350yds if it's a cup/core, a mono, needs more speed/mv for that far.
The potential of a Swede given it's +/- 1.5gr diff in capacity over a 260 Rem, is about identical, maybe 50 fps more w/heavier bullets due to throating also....IMO. SO look at data for the modern 260, and you get the picture.
Few loads here..
http://www.reloadersnest.com/query_bw.asp?CaliberID=120&BulletWeight=140
