"Accurate" is a variable definition. For me and my scoped 6.5's, it means consistent MOA or under.
The two bullets that have proved accurate in all of the many Swedes I've worked with are; Horn. 140 SP, and Horn. 140 Amax.
Both of these bullets have long shanks, allowing them to be seated long, out close to the leade and in some rifles able to touch/jam. When seated to max mag length, there is still plenty of bullet shank in the case neck for a solid, straight, loaded cartridge.
Long and straight, with a stout charge of R22, has always performed well, for me.
The Amax do cost a few bucks more, but are very accurate. My best M38 military barreled, 10x scoped, tuned M96 Swede holds 1/2 MOA with 'em, full match grade loads, out to 500yds or so, and not much more MOA past that distance. Conditions permitting.
139gr Privi's shoot OK, around 2 MOA or so, in the 3 or 4 rifles I've tried them in. They are quite short shanked.