Sorry but I disagree, and so does internet pricing at midway on your brass prices.
First the 338 EDGE (338/300 rum) and 338 Lapua are almost identical in ballistics. But it you want to push the 338 LM in Lapua brass you have the option and it will out preform the EDGE by a very small margin. If you load them both to the max load of, lets say 92 gr of H-1000 with a 300 gr bullet the REM brass will start to have loose primer pockets at 3 or 4 firings. However the Lapua brass will be going strong for long after.
I just checked
www.midwayusa and the cost of REM 300 RUM brass is $109 per 100. The cost of 338 LM is $280 per 100. So once you have tossed 3 sets of the "less expensive brass" and the LM brass is still going strong the LM has now become the better value. If you take into consideration the brass quality the LM wins hands down. So if you cull 20% of the REM now where are you?
Not sure where you got your info but I can tell you after owning both my statements are correct.
Jeff
Hey Jeff...
No doubt that Lapua brass is much better than Remington or Winchester, etc. if Lapua made .300 RUM brass, I would use it! I shoot two different .338 Tejas Wildcats both custom rifles with TBAC .338 supressors. My hunting rifle has a sendero contoured 29" barrel and my competition version has a 32" heavy tactical barrel. which is the 338/300 RUM with at steep (Ackley like but steeper) shoulder. The first rifle I shoot 94.0g of H1000 with 300g Bergers and the second rifle I shoot 95.0g of H1000. I am not going to knock the 338 LM round but my point was that if you are shooting hotter loads you will only get 4 or 5 firings before the primer pockets loosen up. I would rather use and throw away a lower cost Remington .300 RUM piece of brass vs. throwing way a much higher cost piece of Lapua Brass. That was my point.
Question, could you even get 95g in a .338 LM case with a 300g Berger??
Sean Carlock from Defensive Edge was loading 106g of H1000 in his 338+P LRKM but has since backed it down a few grains. Still close to 100g of H1000 though.