I just finished building a 26" Savage 11 in 6x45mm, and IMR has load data for the cartridge online. I was able to work up a 90gr Berger VLD Target over 25.5 grains of 8208 XBR (I haven't chrono'd it yet). I tried seating the bullet up to the lands and I think it was a bit much for this load. All of the .223 once fired brass had slight bulging at the webbing and the primers showed a little flowing. HOWEVER, all of the 5.56 Nato brass that was converted had no signs of excessive pressure on the case, but the primer still had the outie belly button (from flowing). I was able to score a 0.132" three shot group at 100 yards (after subtracting bullet diameter). I have a picture, but I'm having image hosting issues...

I'll see if I can get this load chronographed and we can get some numbers on paper.

Here is a summary:
Rifle:
Savage 11 Action (with Accutrigger)
McGowen 26" Chromoly barrel - 1 in 9" twist
Basic savage 11 tupperware stock
Nikon Prostaff 4-12x40 Mil Dot

Load:
Brass - PMC Bronze .223/Lake City 5.56
Bullet - Berger 90gr VLD Target
Powder - IMR 8208XBR - 25.5gr
Primer - CCI BR-4