Re: .338 LM 1-10 twist, what wieght bullets?
George, if you are trying to build up brass, I have used the Hornady 250 gr and 285 gr factory loads. They are fairly "economical" if you can say that about 338LM, and the cases work very well later. They shot very well, with great groupings, even though I am not an expert marksman.
I have 180 Hornady cases, 100 Lapua cases, and 150 Nosler cases. Haven't shot any Lapua or Nosler yet, and I'm sure the brass is better quality than the Hornady, but my experience, and what I have heard about the Hornady brass, it is nothing to sneeze at---may not be a Mercedes, but it is a luxury car, not a Hyundai.