I have a Browning x-bolt, micro hunter. I believe the twist is 1:9.
Shot 120 grain Rem. core-lokts they shot crappie.
Tried some of my handloads. 139 grain GMX with 41 grains of 4064 moa all day long.
Do not know if that helps. I think the longer bearing surface of the "Mono" bullet helped it.
http://www.riflebarrels.com/products/caliber_twist_rates.htm
