Re: anyone out there shooting the 338 ultra mag?
I have the .338 RUM in 700 LSS. Nice rifle, sub-MOA after some work on it. Put a Vais brake on it to save my shoulder. Have about 350 rounds down the tube this year.
I wish I had a Sendero, as they're more accurate - often sub-MOA out of the box with factory ammo, and the weight would help with the recoil.
My rifle likes the 250 grain Gamekings. 3/4" patter at 2950 fps. Could get up to 3077 fps but the accuracy dropped off. Lighter bullets such as the 225 grain Hornady or Accubonds, or the 200 grain speers are not as accurate. Haven't tried MK's yet, next on my list.
Good gun, commands attention at the range.
Mark in Utah