John,
Vihtavuori is probably the most readily available powder over the counter in Europe, so I am specially appreciative of your article!
550 and 560 have always provided top speeds and very good accuracy, while 140, 150 and 165 have delivered top notch accuracy at not so high speeds.
I yet have to use 555 of which I've got hold of 1kg but will test it soon in my 6,5x57R. Not a CM, but similar in capacity and in an accurate gun as my k95 kipplauf I hope to gets very good results as well. By the way, the Bergara rifle which you used in the CM is selling extremely well in my country and their reputation for accuracy has surpassed that of Tikka. I have sighted in two for two friends and both were ridiculously accurate shooting Hornady commercial ammunition.
Alvaro
