I have used us 869 in the 30-378. I know its not the 338 but case capacity should be close.
With 196 hammer hunter i am getting 3330 and .25 moa.
Us 869 is cheaper and easy to get.
Probably one of the easiest loads I have ever tried.
Was shooting 200 grain accubonds at .5 moa.
I haven't been able to get any bergers to shoot bug holes. from 30 cal to .224
Yes 3/4 moa but after 20-30 rounds i give up because hammers have always shot better for me.