I'm ashamed to say that my wonderful pair of 6.5 molds have never had a single boolit cast from them. I do plan to rectify that situation this winter though.

I know I kept asking this question on shooters, but the thread would always be down several pages of threads by the time I'd look for it, and with the demise of shooters, they would be lost as well.

I did pick up Bruce's comment of 16 gr 2400 was magic, but was also wondering if others had found a sweet spot with Unique, or any other common powder. Due to hazmat and other shipping requirements, I'd have to order 12 8# kegs of surplus powder to make it's purchase economical, but that is too much powder for me, and I can't find enough like minded individuals with cash in hand to make a bulk order, so, surplus powders aren't an option.

11.5 grains of Unique works OK with my rifle.

Oldfeller

.......Naturally pressure and velocity both play a part in accuracy. It appears that velocity is what the 6.5x55 seems to be most sensitive to, for the most part. In early accuracy shooting done with 2 other casters/reloaders we found (as did a multitude of others) that accuracy in the Swede "Goes South" at about normal cast bullet speeds in other cartridges. Beginning usually at about 1700 fps.

Yet using the faster powders in reduced loads to propel the nominally heavy for bore bullets to even moderate velocities, does require a surprising amount of pressure. Shooting cast lead in the Swede to 2K velocities never produced any leading. Hense my belief it's velocity the fast twist is most affected by.

Like BruceB has shown, most any of the common 'faster' cast bullet type powders suitable for rifles, works in the Swede (Bruce's twist being similar) so long as velocities remain lower. I'd say any of the easy to ignite numbers from Unique to the 4198's are good choices. With the Jumptrap original Lee custom bullet (FN design) of about 142grs and 11.5 grs of Unique, it produces target grade accuracy.

This may raise the question of why I like surplus WC860 or WC872 so much in this cartridge. Especially since they are so far removed from the faster end of the burn rate chart. Primarily it's price. With my favorite charge of 32.0 grs, it costs less than the GC or the primer :-). Of course you must learn to deal with a bit of unburned powder, :-).

I never experimented with any of the canister grade mid and slow powders. I can't comment on their viability or suitability in much reduced charges (to maintain correct velocity). I would start with Unique @ 10.0grs and go up in half grain increments until you see your accuracy failing. Then move to the next slower powder and start 'mid-charge' of your previous powder.

Any of these between Unique and the 4198's should give what you want. What you end up staying with may be determined by the powder's useability for other things you'd use it in, thereby simplifying your powder inventory.

.........Buckshot