300 Norma Mag (Standard Version)

[Carey Farmer]

My answer was if I'm going through all those steps, why push back the case capacity instead of running it as a 30-338 LMI?

You're probably right. I should just get over my aversion to fire-forming.

 

[7.62 Gunner]

Don't see a lot of love for the .300 Lapua Magnum. Seems like it would be pretty easy - just neck down, run a full length sizing die to push the neck / shoulder junction back to 25 degree angle, and trim the neck. That will yield a case that's pretty close to .300 Norma Improved capacity I think, with fire-forming not required.

Am I missing something?

The lapua case is still pretty long for 225 elds or 245 eols seated above the donut area.
Also the shorter 300 NM case has a reputation for accuracy and tuning like the wsms, plus 25 degree shoulders stretch quite a bit more than a 40 degree 300 NMI.
I'm not a huge fan of fireforming either, but with Lapua brass100 cases will last forever

 

[QuietTexan]

I should just get over my aversion to fire-forming.

IMO to get the best results every case needs to be shot at least once, whether fireforming to an improved chamber or or not. 50-100 pieces of brass and 1-2x firings on the cases nets about 100 rounds down the barrel, then everything in is in a nice spot to do the load workup.

If you've ever loaded for the chambering before then fireforming loads can be very accurate right out of the gate, just not as fast as ultimately possible afterwards. I go through the extra two steps of setting up a false shoulder on new brass and have taken those loads out to 1400 yards. No wasted barrel life at all, and great case life.