In my experience with the 338lm, the primary issues I experienced were issues in regards to seating/length, thus my comments, however, you are correct because, there is a sleight variation in the cases...So, I apologize, I was incorrect.
Saami vs. CIP
That being said, the CIP cartridge is actually slightly longer than the Saami...
I do agree w/the second half of your statement.
Oye, I addressed this a bit, above.
As I said as well, my primary experiences revolving around the cartridge were of length. I didn't realize the two were actually necked differently.
I was incorrect and I thank you for being informative.