Odd development with Lapua 300 Win Mag Brass

[robert rex]

I have a custom 300 Win Mag that I was reloading using once fired Barnes brass. Rifle always shot 1/3 to a 1/4 MOA. Replaced the brass with virgin Lapua using 71g H4831sc and 180 g Hammer Hunter .030 off jam @ 2980. Still shoots 1/4 MOA with a slight POI shift. So I take the once fired which grows about .010, set the shoulders back .002, trim the necks to same dimension as virgin Lapua, seat to same depth and the POI shifts 1 1/4 low but still 1/3 MOA. I click up .3mil back to center, still 1/3MOA and move out to 600 and the existing ballistic dope is still perfect. I didn't have my chronograph so I couldn't see whether the small increase in case volume from the expanded brass, slowed the bullet slightly or if it was just a POI shift. So after all that, are you all seeing a POI shift from virgin brass to first firing? I never experienced it with the Barnes because it was all once fired and resized.

 

[robert rex]

Oh, I'm annealing but not neck turning.

 

[GLTaylor]

Pretty normal after first (and sometimes second) firing of new brass.