Just in case someone is looking for some more data.I loaded some of the new IMR XBR8308 just to check it out in the 6X45mm.
Data: 25.5gr /68gr Euber bullet/CCI BR4 primer/2853fps
Accuracy was good two 4 shot groups at 100yds measured .715 and .548 and based on looks of primer load was warm but not max....in MY gun.

Since there seems to be a lot of interest in 6X45mm uppers in the AR forum I will make this a sticky for a while and see if it merits it or not.

Edited by venatic (09/27/10 09:38 PM)
"Anyone taking up handloading necessarily plays with unknown factors and takes chances. But so does anyone who drives a car,goes to a cocktail party,eats in a restaurant,or gets married."

Jack O'Connor 1963