Jerry, I am surprised to hear this. In my experiences the with some custom RUM's they were slower than the Lapua and if you loaded them to the same charge as a Lapua the Rem cases were done in only a few firings.
All my experience is with 300 gr bullets.
I can't speak for the .338 Norma as I have never owned one.
Jeff
Yes you are right if you load both cases to "There max" the Lapua will take more pressure and
therefore be as fast or faster.
The Lapua case has less case capacity than the RUM and with the loads at 100% case density
You have to use faster powder to achieve the same velocity with the same approximate
pressure.
I know longer load "Maximum" loads to get velocity, I just go to a larger case. This keeps things
simple and trouble free.
With the Improved Lapua, case capacity is almost identical to the RUM an last much longer
if loaded the same way as the RUM.(But with the Lapua brass loads can be hotter and still
last longer if a person wants to).
I try never to recommend hot loads to anyone I personally don't know because instead of them
starting lower they allways start where I worked up to. (I have a load for a 30/378 that uses
a 200 gr bullet with 126 grains of powder) and it is not maxed out in my rifle because I have
done some things that allow me to reach velocities that are unheard of.
Also I like the 225 and 250gr bullets for hunting and have a different outcome than you will
with the 300 grain bullets In the RUM.
My Ratings are based on Factory ammo only and listed max loads in most reloading books.
I am not always good at explaining things so I felt like you were due an explanation of how
My results differed from yours. So I guess we are both right .
As I said I no longer load to the max(Like I did when I was younger and would load to one
firing of the brass and tossing it). now I just go to a bigger case if I want more velocity Like
the 338/378 or even the excalibur.
I hunt with the 338 RUM and It will do everything that I want and is easy to load, and factory
ammo is available.
I would like to build myself a 338 lapua improved but so far the RUM has performed flawlessly
and it's hard to justify if you know what I meen.
Sorry for the long winded post but I respect your opinion and experance.
J E CUSTOM