Here in Scandinavia, the 6.5 x 55 is as common as dirt. It is used in a LOT of long range competitions.

I do not know what powders you can easily get, but here Vihtavuori N150 or N165 or N550 are often used for long range competition. N550 is perhaps the most common at my local 600 m range, and Lapua's data will give you 2882 fps with 140gr bullets -- and usually fine accuracy.

You can download the complete Vihtavuori Reloading Guide (2012) edition HERE,

Worthwhile downloading it for a reference. Free too!

John